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  Subjects -> CHEMISTRY (Total: 844 journals)
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    - INORGANIC CHEMISTRY (41 journals)
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    - PHYSICAL CHEMISTRY (66 journals)

INORGANIC CHEMISTRY (41 journals)

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Acta Polymerica     Hybrid Journal   (Followers: 9)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Current Methods in Inorganic Chemistry     Full-text available via subscription   (Followers: 2)
European Journal of Inorganic Chemistry     Hybrid Journal   (Followers: 12)
European Polymer Journal     Hybrid Journal   (Followers: 41)
Heterocyclic Communications     Hybrid Journal  
High Performance Polymers     Hybrid Journal   (Followers: 1)
Indian Journal of Chemistry - Section A     Open Access   (Followers: 7)
Inorganic Chemistry     Full-text available via subscription   (Followers: 24)
Inorganic Chemistry Communications     Hybrid Journal   (Followers: 11)
Inorganic Chemistry Frontiers     Full-text available via subscription   (Followers: 3)
Inorganic Materials     Hybrid Journal   (Followers: 4)
Inorganic Materials: Applied Research     Hybrid Journal   (Followers: 1)
Inorganica Chimica Acta     Hybrid Journal   (Followers: 6)
Inorganics     Open Access  
International Journal of Bio-Inorganic Hybrid Nanomaterials     Open Access   (Followers: 1)
International Journal of Inorganic Chemistry     Open Access   (Followers: 2)
JBIC Journal of Biological Inorganic Chemistry     Hybrid Journal   (Followers: 5)
Journal of Inorganic and Organometallic Polymers and Materials     Partially Free   (Followers: 9)
Journal of Inorganic Biochemistry     Hybrid Journal   (Followers: 6)
Journal of Polymer Engineering     Hybrid Journal   (Followers: 9)
Journal of Polymers and the Environment     Hybrid Journal   (Followers: 1)
Journal of Separation Science     Hybrid Journal   (Followers: 11)
Metallodrugs     Open Access   (Followers: 1)
Open Journal of Inorganic Chemistry     Open Access   (Followers: 2)
Plasmas and Polymers     Hybrid Journal  
Polymer Bulletin     Hybrid Journal   (Followers: 7)
Polymer Composites     Hybrid Journal   (Followers: 15)
Polyoxometalate Chemistry     Open Access  
Reviews in Inorganic Chemistry     Hybrid Journal  
Russian Journal of Inorganic Chemistry     Hybrid Journal  
Studies in Inorganic Chemistry     Full-text available via subscription  
Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry     Hybrid Journal   (Followers: 1)
Topics in Inorganic and General Chemistry     Full-text available via subscription  
Zeitschrift für anorganische und allgemeine Chemie     Hybrid Journal   (Followers: 2)
Zeitschrift für Kristallographie - New Crystal Structures     Open Access  
Journal Cover Journal of Inorganic Biochemistry
  [SJR: 0.983]   [H-I: 100]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0162-0134
   Published by Elsevier Homepage  [3043 journals]
  • Water-soluble metalloporphyrinates with excellent photo-induced anticancer
           activity resulting from high tumor accumulation
    • Authors: Xiaojun Hu; Kazuma Ogawa; Tatsuto Kiwada; Akira Odani
      Pages: 1 - 7
      Abstract: Publication date: May 2017
      Source:Journal of Inorganic Biochemistry, Volume 170
      Author(s): Xiaojun Hu, Kazuma Ogawa, Tatsuto Kiwada, Akira Odani
      To develop a water-soluble and tumor-targeted photosensitizer for photodynamic therapy (PDT), a porphyrin framework containing the metal ion gallium(III) was combined with platinum(II)-based groups to produce two new pentacationic metalloporphyrinates, Ga-4cisPtTPyP (5,10,15,20-tetrakis{cis-diammine-chloro-platinum(II)}(4-pyridyl)-porphyrinato gallium(III) hydroxide tetranitrate) and Ga-4transPtTPyP (5,10,15,20-tetrakis{trans-diammine-chloro-platinum(II)} (4-pyridyl)-porphyrinato gallium(III) hydroxide tetranitrate). Both complexes exhibited high singlet oxygen quantum yields (Φ∆) and remarkable photocytotoxicity with appreciable phototoxic indexes (PIs). In particular, Ga-4cisPtTPyP showed a low IC50 value (Colon 26: 0.12μM; Sarcoma 180: 0.08μM) under illumination and its PI up to 1000. With outstanding tumor accumulation (tumor/muscle ratio>9), Ga-4cisPtTPyP almost completely inhibited tumor growth over two weeks in an in vivo PDT assay. These results imply that Ga-4cisPtTPyP could be a promising anticancer agent for use in PDT.
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      PubDate: 2017-02-09T11:16:19Z
      DOI: 10.1016/j.jinorgbio.2017.02.001
      Issue No: Vol. 170 (2017)
       
  • The dissociation of the Hsp60/pro-Caspase-3 complex by
           bis(pyridyl)oxadiazole copper complex (CubipyOXA) leads to cell death in
           NCI-H292 cancer cells
    • Authors: Celeste Caruso Bavisotto; Dragana Nikolic; Antonella Marino Gammazza; Rosario Barone; Filippa Lo Cascio; Emanuele Mocciaro; Giovanni Zummo; Everly Conway de Macario; Alberto JL Macario; Francesco Cappello; Valentina Giacalone; Andrea Pace; Giampaolo Barone; Antonio Palumbo Piccionello; Claudia Campanella
      Pages: 8 - 16
      Abstract: Publication date: May 2017
      Source:Journal of Inorganic Biochemistry, Volume 170
      Author(s): Celeste Caruso Bavisotto, Dragana Nikolic, Antonella Marino Gammazza, Rosario Barone, Filippa Lo Cascio, Emanuele Mocciaro, Giovanni Zummo, Everly Conway de Macario, Alberto JL Macario, Francesco Cappello, Valentina Giacalone, Andrea Pace, Giampaolo Barone, Antonio Palumbo Piccionello, Claudia Campanella
      Cell survival and proliferation are central to carcinogenesis, involving various mechanisms among which those that impede apoptosis are important. In this, the role of the molecular chaperone Hsp60 is unclear since it has been reported that it can be both, pro- or anti-apoptotic. A solution to this riddle is crucial to the development of anti-cancer therapies targeting Hsp60. We addressed this question using a tumor cell line, NCI-H292, and [Cu(3,5-bis(2′-pyridyl)-1,2,4-oxadiazole)2(H2O)2](ClO4)2, CubipyOXA, a copper-containing compound with cytotoxic properties. We treated cells with various doses of the compound and measured cell viability; apoptosis indicators; and levels of Hsp60, pro-Caspase-3 (pC3), Caspase-3 (C3), and complex Hsp60/pC3, with complementary methods. The quantitative dose-response curves of the levels of Hsp60, activated C3, inactivated pC3, Hsp60/pC3 complex and indicators of cell apoptosis, and cell death, all coincided to show that CubipyOXA has pro-apoptotic activity and promotes cell death. The curves also indicate that the pro-apoptotic effects of CubipyOXA could likely be due to a lowering of Hsp60 levels and to its blocking the formation of the Hsp60/pC3 complex and/or its dissociating the complex when already formed, thus, interfering with the anti-apoptotic action of Hsp60. These findings shed some light on how a tumor cell may avert apoptosis using Hsp60 and point to the anti-cancer potential of drugs, such as CubipyOXA, which interfere with Hsp60/pC3 complex formation, and thus allow the apoptotic cascade to proceed. In view of these findings it becomes clear that the novel compound CubipyOXA should be considered a potential, high-efficiency antitumor agent deserving further testing.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.004
      Issue No: Vol. 170 (2017)
       
  • EPR and photophysical characterization of six bioactive oxidovanadium(IV)
           complexes in the conditions of in vitro cell tests
    • Authors: Marta Lovisari; Giorgio Volpi; Domenica Marabello; Silvano Cadamuro; Annamaria Deagostino; Eliano Diana; Alessandro Barge; Margherita Gallicchio; Valentina Boscaro; Elena Ghibaudi
      Pages: 55 - 62
      Abstract: Publication date: May 2017
      Source:Journal of Inorganic Biochemistry, Volume 170
      Author(s): Marta Lovisari, Giorgio Volpi, Domenica Marabello, Silvano Cadamuro, Annamaria Deagostino, Eliano Diana, Alessandro Barge, Margherita Gallicchio, Valentina Boscaro, Elena Ghibaudi
      A number of oxidovanadium(IV) complexes have been reported to display anticancer activity. A theranostic approach, based on the simultaneous observation of both the effect of oxidovanadium(IV) complexes on cell viability and the disclosure of their intracellular fate, is possible by using oxidovanadium(IV) complexes functionalized with fluorescent ligands. In the present study we accomplished the characterization of six oxidovanadium(IV) complexes in conditions close to those employed for in vitro administration. In particular, we investigated the light harvesting properties of such complexes in the presence of a dimethylsulphoxide/aqueous buffer mixture, and we found that one complex exhibits a quantum yield suitable for confocal microscopy investigations. EPR investigations in the same conditions provide information about the presence of ligands' substitution processes. Finally, the electrochemical properties of all complexes were determined by cyclic voltammetry. The overall results show that these complexes exhibit an average stability in solution; EPR data confirm that DMSO enter the first coordination sphere of oxidovanadium(IV) and suggest the occurrence of partial ligand substitution in the dimethylsulphoxide/aqueous buffer mixture.
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      PubDate: 2017-03-20T16:57:09Z
      DOI: 10.1016/j.jinorgbio.2017.02.009
      Issue No: Vol. 170 (2017)
       
  • Rhenium(I) tricarbonyl compounds of bioactive thiosemicarbazones:
           Synthesis, characterization and activity against Trypanosoma cruzi
    • Authors: Esteban Rodríguez Arce; Ignacio Machado; Belén Rodríguez; Michel Lapier; María Carolina Zúñiga; Juan Diego Maya; Claudio Olea Azar; Lucía Otero; Dinorah Gambino
      Pages: 125 - 133
      Abstract: Publication date: May 2017
      Source:Journal of Inorganic Biochemistry, Volume 170
      Author(s): Esteban Rodríguez Arce, Ignacio Machado, Belén Rodríguez, Michel Lapier, María Carolina Zúñiga, Juan Diego Maya, Claudio Olea Azar, Lucía Otero, Dinorah Gambino
      American Trypanosomiasis is a chronic infection discovered and described in 1909 by the Brazilian scientist Carlos Chagas. It is caused by the protozoan parasite Trypanosoma cruzi. Although it affects about 10million people in Latin America, the current chemotherapy is still inadequate. The discovery of new drugs is urgently needed. Our group is focused on the development of prospective metal-based drugs mainly based on bioactive ligands and pharmacologically interesting metal ions. In this work three new rhenium(I) tricarbonyl compounds fac-[ReI(CO)3Br(HL)] where HL=5-nitrofuryl containing thiosemicarbazones were synthesized and fully characterized in solution and in the solid state. The in vitro evaluation of the compounds on T. cruzi trypomastigotes (Dm28c strain) showed that the Re(I) compounds are 8 to 15 times more active than the reference drug Nifurtimox and show a 4 to 17 fold increase in activity in respect to the free (HL) ligands. Obtained compounds also show good selectivity indexes (IC50 endothelial cells Ea.hy926/IC50 T. cruzi (Dm28c tripomastigotes)). 1H NMR and MS studies, performed with time, showed that the fac-[Re(CO)3Br(HL)] species convert into the dimers [Re2(CO)6(L)2] in solution. Crystal structure of [ReI 2(CO)6(L2)2], the product of complexes' dimerization, was solved. Related to the mechanism of action, the studied compounds do not generate radical oxygen species in the parasite (as 5-nitrofuryl derived thiosemicarbazones do) probably due to the unfavorable nitro reduction potential of the generated dimeric species. On the contrary, the compounds produce a decrease of the oxygen consumption rate of the parasites, maybe inhibiting their mitochondrial respiration.
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      PubDate: 2017-03-01T08:25:56Z
      DOI: 10.1016/j.jinorgbio.2017.01.011
      Issue No: Vol. 170 (2017)
       
  • A moderate metal-binding hydrazone meets the criteria for a bioinorganic
           approach towards Parkinson's disease: Therapeutic potential, blood-brain
           barrier crossing evaluation and preliminary toxicological studies
    • Authors: Daphne Schneider Cukierman; Ana Beatriz Pinheiro; Sergio L.P. Castiñeiras-Filho; Anastácia Sá P. da Silva; Marco C. Miotto; Anna De Falco; Thales de P. Ribeiro; Silvia Maisonette; Alessandra L.M.C. da Cunha; Rachel A. Hauser-Davis; J. Landeira-Fernandez; Ricardo Q. Aucélio; Tiago F. Outeiro; Marcos D. Pereira; Claudio O. Fernández; Nicolás A. Rey
      Pages: 160 - 168
      Abstract: Publication date: May 2017
      Source:Journal of Inorganic Biochemistry, Volume 170
      Author(s): Daphne Schneider Cukierman, Ana Beatriz Pinheiro, Sergio L.P. Castiñeiras-Filho, Anastácia Sá P. da Silva, Marco C. Miotto, Anna De Falco, Thales de P. Ribeiro, Silvia Maisonette, Alessandra L.M.C. da Cunha, Rachel A. Hauser-Davis, J. Landeira-Fernandez, Ricardo Q. Aucélio, Tiago F. Outeiro, Marcos D. Pereira, Claudio O. Fernández, Nicolás A. Rey
      Alzheimer's and Parkinson's diseases share similar amyloidogenic mechanisms, in which metal ions might play an important role. In this last neuropathy, misfolding and aggregation of α-synuclein (α-Syn) are crucial pathological events. A moderate metal-binding compound, namely, 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone (INHHQ), which was previously reported as a potential ‘Metal-Protein Attenuating Compound’ for Alzheimer's treatment, is well-tolerated by healthy Wistar rats and does not alter their major organ weights, as well as the tissues' reduced glutathione and biometal levels, at a concentration of 200mgkg−1. INHHQ definitively crosses the blood-brain barrier and can be detected in the brain of rats so late as 24h after intraperitoneal administration. After 48h, brain clearance is complete. INHHQ is able to disrupt, in vitro, anomalous copper-α-Syn interactions, through a mechanism probably involving metal ions sequestering. This compound is non-toxic to H4 (human neuroglioma) cells and partially inhibits intracellular α-Syn oligomerization. INHHQ, thus, shows definite potential as a therapeutic agent against Parkinson's as well.
      Graphical abstract image

      PubDate: 2017-03-01T08:25:56Z
      DOI: 10.1016/j.jinorgbio.2017.02.020
      Issue No: Vol. 170 (2017)
       
  • Cadmium-induced endoplasmic reticulum stress in chicken neutrophils is
           alleviated by selenium
    • Authors: Jianqiao Chen; Tingru Pan; Na Wan; Zhepeng Sun; Ziwei Zhang; Shu Li
      Pages: 169 - 177
      Abstract: Publication date: May 2017
      Source:Journal of Inorganic Biochemistry, Volume 170
      Author(s): Jianqiao Chen, Tingru Pan, Na Wan, Zhepeng Sun, Ziwei Zhang, Shu Li
      Cadmium (Cd) decreases immune function and induces apoptosis of immune cells. Selenium (Se) can antagonize some metal element toxicity including Cd. To evaluate the cytotoxicity of Cd and the chemoprotective role of Se on bird neutrophils in vitro, we incubated chicken neutrophils cells with Cadmium chloride (CdCl2) (10−6 M), Sodium selenite (Na2SeO3) (10−7 M), and with a mixture of Na2SeO3 (10−7 M) and CdCl2 (10−6 M) for 12, 24, 36, and 48h. We found that Interleukin 1β (IL-1β), Interleukin 10 (IL-10), and interferon gamma (IFN-γ) increased and interleukin 17 (IL-17), interleukin 4 (IL-4) decreased significantly in the chicken neutrophils of the Cd treatment groups. Cd significantly increased the mRNA expression levels of nuclear factor kappaB (NF-κB), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α), and prostaglandin E2 (PGE2) and the nitric oxide (NO) content. In addition, we demonstrated that Cd induced the apoptosis of chicken neutrophils and increased mRNA level of Bak, Cysteine-aspartic protease (Caspase)-3, Caspase-9, Caspase-12, glucose-regulated protein 78 (GRP78) and activating transcription factor 6 (ATF6), decreased mRNA level of Bcl-xl, and Ca/calmodulin-dependent protein (CaM). Moreover, the expression of NF-κB and Caspase-12 protein increased significantly in the Cd treatment groups. Se pretreatment significantly protected neutrophils against Cd-caused alterations. Our work suggested that Cd-induced immune suppression, inflammatory response, and apoptosis via endoplasmic reticulum stress (ERS). Moreover, these factors played critical roles in Se-mediated chemoprevention against Cd-induced immunotoxicity.
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      PubDate: 2017-03-01T08:25:56Z
      DOI: 10.1016/j.jinorgbio.2017.02.022
      Issue No: Vol. 170 (2017)
       
  • New 4′-(4-chlorophenyl)-2,2′:6′,2″-terpyridine ruthenium(II)
           complexes: Synthesis, characterization, interaction with DNA/BSA and
           cytotoxicity studies
    • Authors: Milan M. Milutinović; Ana Rilak; Ioannis Bratsos; Olivera Klisurić; Milan Vraneš; Nevenka Gligorijević; Siniša Radulović; Živadin D. Bugarčić
      Pages: 1 - 12
      Abstract: Publication date: April 2017
      Source:Journal of Inorganic Biochemistry, Volume 169
      Author(s): Milan M. Milutinović, Ana Rilak, Ioannis Bratsos, Olivera Klisurić, Milan Vraneš, Nevenka Gligorijević, Siniša Radulović, Živadin D. Bugarčić
      In this study, we have developed a series of new monofunctional Ru(II) complexes of the general formula mer-[Ru(Cl-Ph-tpy)(N-N)Cl]Cl in which Cl-Ph-tpy is 4′-(4-chlorophenyl)-2,2′:6′,2″-terpyridine, N-N is a bidentate chelating ligand (1,2-diaminoethane (en, 1), 1,2-diaminocyclohexane (dach, 2) or 2,2′-bipyridine (bpy, 3)). All complexes were fully characterized by elemental analysis and spectroscopic techniques (IR, UV–Vis, 1D and 2D NMR). Their chemical behavior in aqueous solution was studied by UV–Vis and NMR spectroscopy showing that all compounds are relatively labile leading to the formation of the corresponding aqua species 1aq–3aq. Their DNA binding ability was evaluated by UV–Vis spectroscopy, fluorescence quenching measurements and viscosity measurements. Competitive studies with ethidium bromide (EB) showed that the complexes can displace DNA-bound EB, suggesting strong competition with EB (K sv =1.1–2.7×104 M−1). These experiments show that the ruthenium complexes interact with DNA via intercalation. The complexes bind to serum protein albumin displaying relatively high binding constants (K sv =104–105 M−1). Compound 3 displayed from high to moderate cytotoxicity against two cancer cell lines HeLa and A549 (with IC50 ca. 12.7μM and 53.8μM, respectively), while complexes 1 and 2 showed only moderate cytotoxicity (with IC50 ca. 84.8μM and 96.3μM, respectively) against HeLa cells. The cell cycle analysis (by flow cytometry) of HeLa and A549 cells treated with complex 3 shows minor changes on the cell cycle phase distribution.
      Graphical abstract image

      PubDate: 2017-01-13T22:45:42Z
      DOI: 10.1016/j.jinorgbio.2016.10.001
      Issue No: Vol. 169 (2017)
       
  • Heterologous expression of Halomonas halodenitrificans nitric oxide
           
    • Authors: Nobuhiko Sakurai; Kunishige Kataoka; Noriko Sugaya; Takaki Shimodaira; Mie Iwamoto; Munehiro Shoda; Hajime Horiuchi; Miyuki Kiyono; Yasuke Ohta; Bambang Triwiyono; Daisuke Seo; Takeshi Sakurai
      Pages: 61 - 67
      Abstract: Publication date: April 2017
      Source:Journal of Inorganic Biochemistry, Volume 169
      Author(s): Nobuhiko Sakurai, Kunishige Kataoka, Noriko Sugaya, Takaki Shimodaira, Mie Iwamoto, Munehiro Shoda, Hajime Horiuchi, Miyuki Kiyono, Yasuke Ohta, Bambang Triwiyono, Daisuke Seo, Takeshi Sakurai
      Halomonas halodenitrificans nitric oxide reductase (NOR) is the membrane-bound heterodimer complex of NorC, which contains a low-spin heme c center, and NorB, which contains a low-spin heme b center, a high-spin heme b 3 center, and a non-heme FeB center. The soluble domain of NorC, NorC* (ΔMet1–Val37) was heterologously expressed in Escherichia coli using expression plasmids harboring the truncated norC gene deleted of its 84 5′-terminal nucleotides. Analogous scission of the N-terminal helix as the membrane anchor took place when the whole norC gene was used. NorC* exhibited spectra typical of a low-spin heme c. In addition, NorC* functioned as the acceptor of an electron from a cytochrome c isolated from the periplasm of H. halodenitrificans and small reducing reagents. The redox potential of NorC* shifted ca. 40mV in the negative direction from that of NorC. Unlike NorC, recombinant NorB was not heterologously expressed. However, recombinant NOR (rNOR) could be expressed in E. coli by using a plasmid harboring all genes in the nor operon, norCBQDX, from which the three hairpin loops (mRNA) were deleted, and by using the ccm genes for the maturation of C-type heme. rNOR exhibited the same spectroscopic properties and reactivity to NO and O2 as NOR, although its enzymatic activity toward NO was considerably decreased. These results on the expression of rNOR and NorC* will allow us to develop more profound studies on the properties of the four Fe centers and the reaction mechanism of NOR from this halophilic denitrifying bacterium.
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      PubDate: 2017-01-28T01:05:19Z
      DOI: 10.1016/j.jinorgbio.2017.01.006
      Issue No: Vol. 169 (2017)
       
  • New copper(I) and heteronuclear copper(I)–ruthenium(II) complexes:
           Synthesis, structural characterization and cytotoxicity
    • Authors: João Lopes; David Alves; Tânia S. Morais; Paulo J. Costa; M. Fátima M. Piedade; Fernanda Marques; Maria J. Villa de Brito; M. Helena Garcia
      Pages: 68 - 78
      Abstract: Publication date: Available online 23 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): João Lopes, David Alves, Tânia S. Morais, Paulo J. Costa, M. Fátima M. Piedade, Fernanda Marques, Maria J. Villa de Brito, M. Helena Garcia
      A new family of copper(I) complexes of general formula [Cu(dppe)(NN)]+ have been synthesized and fully characterized, with dppe=1.2-bis(diphenylphosphino)ethane and NN representing several bidentate heteroaromatic ligands: 2,2′-bipy=2.2′-bipyridine (1), Me2bpy=4.4′-dimethyl-2,2′-bipyridine (2), dpytz=3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (3), dpp=2.3-bis(2-pyridyl)pyrazine (4), and the metallaligand [Ru(η5-C5H5)(PPh3)(dpp)]+ (5), yielding the bimetallic copper(I)-ruthenium(II) complex [Cu(dppe)(μ-dpp)Ru(η5-C5H5)(PPh3)]2+ (6). The single crystal structures of complexes (2) and (4) were determined by X-ray diffraction studies. All the complexes exhibit high cytotoxicity against the human cancer cells A2780 and MCF7 far lower than those found for the antitumor drug cisplatin in the same cell lines and even surpassing cisplatin resistance in the A2780cisR cells. They display IC50 values on the human embryonic kidney HEK293 non-tumoral cells of the same order of magnitude as those found for the tumoral cells. In the ovarian cells the compounds induce rapid production of reactive oxygen species (ROS) probably through mitochondrial pathways. According to the results reported here, these compounds can be considered as prospective antitumoral agents that deserve further evaluation.
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      PubDate: 2017-01-28T01:05:19Z
      DOI: 10.1016/j.jinorgbio.2017.01.007
      Issue No: Vol. 169 (2017)
       
  • New tris(dopamine) derivative as an iron chelator. Synthesis, solution
           thermodynamic stability, and antioxidant research
    • Authors: Qingchun Zhang; Bo Jin; Zhaotao Shi; Xiaofang Wang; Shan Lei; Xingyan Tang; Hua Liang; Qiangqiang Liu; Mei Gong; Rufang Peng
      Abstract: Publication date: Available online 21 March 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Qingchun Zhang, Bo Jin, Zhaotao Shi, Xiaofang Wang, Shan Lei, Xingyan Tang, Hua Liang, Qiangqiang Liu, Mei Gong, Rufang Peng
      A new tris(dopamine) derivative, containing three dopamine chelate moieties which were attached to a trimesic acid molecular scaffold, has been prepared and fully characterized by NMR, FTIR and HRMS. The solution thermodynamic stability of the chelator with Fe(III), Mg(II), Zn(II) and Fe(II) ions was investigated. Results demonstrated that the chelator exhibited effective binding ability and improved selectivity to Fe(III) ion. The chelator possessed affinity similar to that of diethylenetriaminepentaacetic acid chelator for Fe(III) ion. The high affinity could be attributed to the favorable geometric arrangement between the chelator and Fe(III) ion coordination preference. The chelator also exhibited high antioxidant activity and nontoxicity to neuron-like rat pheochromocytoma cells. Hence, the chelator could be used as chelating agent for iron overload situations without depleting essential metal ions, such as Mg(II) and Zn(II) ions.
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      PubDate: 2017-03-27T13:49:43Z
      DOI: 10.1016/j.jinorgbio.2017.03.003
       
  • Effect of the protein ligand in DMSO reductase studied by computational
           methods
    • Authors: Geng Dong; Ulf Ryde
      Abstract: Publication date: Available online 21 March 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Geng Dong, Ulf Ryde
      The DMSO reductase family is the largest and most diverse family of mononuclear molybdenum oxygen-atom-transfer proteins. Their active sites contain a Mo ion coordinated to two molybdopterin ligands, one oxo group in the oxidised state, and one additional, often protein-derived ligand. We have used density-functional theory to evaluate how the fourth ligand (serine, cysteine, selenocysteine, OH−, O2−, SH−, or S2−) affects the geometries, reaction mechanism, reaction energies, and reduction potentials of intermediates in the DMSO reductase reaction. Our results show that there are only small changes in the geometries of the reactant and product states, except from the elongation of the MoX bond as the ionic radius of XO, S, Se increases. The five ligands with a single negative charge gave an identical two-step reaction mechanism, in which DMSO first binds to the reduced active site, after which the SO bond is cleaved, concomitantly with the transfer of two electrons from Mo in a rate-determining second transition state. The five models gave similar activation energies of 69–85kJ/mol, with SH− giving the lowest barrier. In contrast, the O2− and S2− ligands gave much higher activation energies (212 and 168kJ/mol) and differing mechanisms (a more symmetric intermediate for O2− and a one-step reaction without any intermediate for S2−). The high activation energies are caused by a less exothermic reaction energy, 13–25kJ/mol, and by a more stable reactant state owing to the strong MoO2− or MoS2− bonds.
      Graphical abstract image

      PubDate: 2017-03-27T13:49:43Z
      DOI: 10.1016/j.jinorgbio.2017.03.004
       
  • Redox behavior and biological properties of ferrocene bearing porphyrins
    • Authors: Rainer Lippert; Tatyana E. Shubina; Sandra Vojnovic; Aleksandar Pavic; Jovana Veselinovic; Jasmina Nikodinovic-Runic; Nada Stankovic; Ivana Ivanović-Burmazović
      Abstract: Publication date: Available online 21 March 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Rainer Lippert, Tatyana E. Shubina, Sandra Vojnovic, Aleksandar Pavic, Jovana Veselinovic, Jasmina Nikodinovic-Runic, Nada Stankovic, Ivana Ivanović-Burmazović
      In order to improve antimicrobial effects of previously studied meso-tetrakis(4-ferrocenylphenyl)porphyrin 1, we have modified its structure by replacing two trans-positioned ferrocenylphenyl moieties with methoxy methylene substituted tert-butylphenyl moieties. Newly synthesized 54,154-bis-(ferrocenyl)-104,204-bis-(tert-butyl)-102,106,202,206-tetrakis-(methoxy-methylene)-5,10,15,20-tetraphenylporphyrin 4 was chemically characterized in detail (by NMR, UV/Vis, IR, MALDI-TOF and ESI MS spectrometry, cyclic voltammetry, prediction of the relative lipophilicity as well as computational methods) and its biological effects were studied in terms of its antibacterial and antifungal activity (both with and without photoactivation), cytotoxicity, hemolysis and DNA cleavage. New ferrocene bearing porphyrin 4 has demonstrated a broader antimicrobial spectrum and modified effects on eukaryotic cells compared to 1. This was discussed in terms of its i) increased lipophilicity, while exhibiting lower toxicity, and ii) the redox potential of a two-electron process that is shifted to lower values, in comparison to ferrocene, thus, entering the physiologically available range and being activated towards redox interactions with biomolecules.
      Graphical abstract image

      PubDate: 2017-03-27T13:49:43Z
      DOI: 10.1016/j.jinorgbio.2017.03.002
       
  • Interaction of a chelating agent,
           5-hydroxy-2-(hydroxymethyl)pyridin-4(1H)-one, with Al(III), Cu(II) and
           Zn(II) ions
    • Authors: Massimiliano Peana; Serenella Medici; Valeria Marina Nurchi; Joanna I. Lachowicz; Guido Crisponi; Eugenio Garribba; Daniele Sanna; Maria Antonietta Zoroddu
      Abstract: Publication date: Available online 16 March 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Massimiliano Peana, Serenella Medici, Valeria Marina Nurchi, Joanna I. Lachowicz, Guido Crisponi, Eugenio Garribba, Daniele Sanna, Maria Antonietta Zoroddu
      5-Hydroxy-2-(hydroxymethyl)pyridin-4(1H)-one ligand, an iron chelator, was evaluated for its coordination ability toward Al(III), Cu(II) and Zn(II) ions by using potentiometric, NMR, EPR and UV–Vis techniques. The behavior of the ligand with the non-essential Al(III) ion has been examined, as well as its potential influence on the homeostatic equilibria of the essential Cu(II) and Zn(II) ions. Structural information on the complex formation equilibria have been obtained from 1D and 2D NMR study. The donor atoms involved in the coordination of Al(III), Cu(II) and Zn(II) ions are (O, O) the same as for Fe(III) at physiological pH value, even if from the complexation competition study the ligand appears to be more selective toward Fe(III) ions supporting that it can be used as an iron chelating agent. The involvement of N-donor atoms at high pH in Cu(II) coordination has been determined by using EPR and UV–Vis techniques.
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      PubDate: 2017-03-20T16:57:09Z
      DOI: 10.1016/j.jinorgbio.2017.03.001
       
  • Interactions of nitrite with catalase: Enzyme activity and reaction
           kinetics studies
    • Authors: Justyna Krych-Madej; Lidia Gebicka
      Abstract: Publication date: Available online 24 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Justyna Krych-Madej, Lidia Gebicka
      Catalase, a heme enzyme, which catalyzes decomposition of hydrogen peroxide to water and molecular oxygen, is one of the main enzymes of the antioxidant defense system of the cell. Nitrite, used as a food preservative has long been regarded as a harmful compound due to its ability to form carcinogenic nitrosamines. Recently, much evidence has been presented that nitrite plays a protective role as a nitric oxide donor under hypoxic conditions. In this work the effect of nitrite on the catalytic reactions of catalase was studied. Catalase was inhibited by nitrite, and this process was pH-dependent. IC50 values varied from about 1μM at pH5.0 to about 150μM of nitrite at pH7.4. The presence of chloride significantly enhanced nitrite-induced catalase inhibition, in agreement with earlier observations. The kinetics of the reactions of nitrite with ferric catalase, its redox intermediate, Compound I, and catalase inactive form, Compound II, was also studied. Possible mechanisms of nitrite-induced catalase inhibition are analyzed and the biological consequences of the reactions of catalase with nitrite are discussed.
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      PubDate: 2017-03-01T08:25:56Z
      DOI: 10.1016/j.jinorgbio.2017.02.023
       
  • Cobalt-based paramagnetic probe to study RNA-protein interactions by NMR
    • Authors: Leah M. Seebald; Christopher M. DeMott; Srivathsan Ranganathan; Papa Nii Asare Okai; Anastasia Glazunova; Alan Chen; Alexander Shekhtman; Maksim Royzen
      Abstract: Publication date: Available online 24 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Leah M. Seebald, Christopher M. DeMott, Srivathsan Ranganathan, Papa Nii Asare Okai, Anastasia Glazunova, Alan Chen, Alexander Shekhtman, Maksim Royzen
      Paramagnetic resonance enhancement (PRE) is an NMR technique that allows studying three-dimensional structures of RNA-protein complexes in solution. RNA strands are typically spin labeled using nitroxide reagents, which provide minimal perturbation to the native structure. The current work describes an alternative approach, which is based on a Co2+-based probe that can be covalently attached to RNA in the vicinity of the protein's binding site using ‘click’ chemistry. Similar to nitroxide spin labels, the transition metal based probe is capable of attenuating NMR signal intensities from protein residues localized <40Å away. The extent of attenuation is related to the probe's distance, thus allowing constructing the protein's contact surface map. This new paradigm has been applied to study binding of HIV-1 nucleocapsid protein, NCp7, to a model RNA pentanucleotide.
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      PubDate: 2017-03-01T08:25:56Z
      DOI: 10.1016/j.jinorgbio.2017.02.024
       
  • [Au(pyb-H)(mnt)]: A novel gold(III) 1,2-dithiolene cyclometalated complex
           with antimicrobial activity (pyb-H=C-deprotonated 2-benzylpyridine;
           mnt2−=1,2-dicyanoethene-1,2-dithiolate)
    • Authors: Anna Pintus; M. Carla Aragoni; Maria A. Cinellu; Laura Maiore; Francesco Isaia; Vito Lippolis; Germano Orrù; Enrica Tuveri; Antonio Zucca; Massimiliano Arca
      Abstract: Publication date: Available online 22 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Anna Pintus, M. Carla Aragoni, Maria A. Cinellu, Laura Maiore, Francesco Isaia, Vito Lippolis, Germano Orrù, Enrica Tuveri, Antonio Zucca, Massimiliano Arca
      The novel heteroleptic cyclometalated complex [AuIII(pyb-H)(mnt)] (1; pyb-H=C-deprotonated 2-benzylpyridine; mnt2 − =1,2-dicyanoethene-1,2-dithiolate) was tested against a panel of ten Gram positive (belonging to the Staphylococcus, Streptococcus spp. and Bacillus clausii), Gram negative (E. coli, K. pneumoniae, P. aeruginosa) bacteria and three yeasts belonging to the Candida spp. Complex 1 showed a remarkable bacteriostatic antimicrobial activity against staphylococci, with Minimum Inhibitory Concentration (MIC) values of 1.56 and 3.13μg/mL for S. haemoliticus and S. aureus, respectively. Spectroscopic and electrochemical measurements, supported by Density Functional Theory (DFT) calculations, were exploited to fully investigate the electronic structure of complex 1 and its relationship with the antimicrobial activity.
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      PubDate: 2017-03-01T08:25:56Z
      DOI: 10.1016/j.jinorgbio.2017.02.015
       
  • Inhibition of amyloid peptide fibril formation by gold–sulfur
           complexes
    • Authors: Wenji Wang; Cong Zhao; Dengsen Zhu; Gehui Gong; Weihong Du
      Abstract: Publication date: Available online 21 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Wenji Wang, Cong Zhao, Dengsen Zhu, Gehui Gong, Weihong Du
      Amyloid-related diseases are characterized by protein conformational change and amyloid fibril deposition. Metal complexes are potential inhibitors of amyloidosis. Nitrogen-coordinated gold complexes have been used to disaggregate prion neuropeptide (PrP106-126) and human islet amyloid polypeptide (hIAPP). However, the roles of metal complexes in peptide fibril formation and related bioactivity require further exploration. In this work, we investigated the interactions of amyloid peptides PrP106-126 and hIAPP with two tetracoordinated gold–sulfur complexes, namely, dichloro diethyl dithiocarbamate gold complex and dichloro pyrrolidine dithiocarbamate gold complex. We also determined the effects of these complexes on peptide-induced cytotoxicity. Thioflavin T assay, morphological characterization, and particle size analysis indicated that the two gold–sulfur complexes effectively inhibited the fibrillation of the amyloid peptides, which led to the formation of nanoscale particles. The complexes reduced the cytotoxicity induced by the amyloid peptides. Intrinsic fluorescence, nuclear magnetic resonance, and mass spectrometry revealed that the complexes interacted with PrP106-126 and hIAPP via metal coordination and hydrophobic interaction, which improved the inhibition and binding of the two gold–sulfur compounds. Our study provided new insights into the use of tetracoordinated gold–sulfur complexes as drug candidates against protein conformational disorders.
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      PubDate: 2017-02-21T16:04:25Z
      DOI: 10.1016/j.jinorgbio.2017.02.021
       
  • Apigenin-7-O-glucoside oxidation catalyzed by P450-bioinspired systems
    • Authors: Lucas B. Bolzon; Joicy S. dos Santos; Denise B. Silva; Eduardo J. Crevelin; Luiz A.B. Moraes; Norberto P. Lopes; Marilda D. Assis
      Abstract: Publication date: Available online 20 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Lucas B. Bolzon, Joicy S. dos Santos, Denise B. Silva, Eduardo J. Crevelin, Luiz A.B. Moraes, Norberto P. Lopes, Marilda D. Assis
      Apigenin-7-O-glucoside (A7G) is the main flavonoid of Bidens gardneri Bak., a Brazilian plant with wide application in folk medicine. Despite the popular use of this plant, its biological effects are not completely known. This work tested the 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin iron(III) and manganese(III) chloride (Fe(TFPP)Cl and Mn(TFPP)Cl), and Jacobsen's catalyst as P450-bioinspired catalysts for A7G oxidation by different oxidants (PhIO, H2O2, m-CPBA, and t-BuOOH). Up to nine different products were detected by HPLC analysis; Reactions with metalloporphyrin/PhIO systems afforded high catalytic conversions (58–89%). In spite of providing smaller product yields, the metalloporphyrin/H2O2 systems led to superior product distribution. Fe(TFPP)Cl yielded the highest A7G conversion rates (79–93%) with the four different oxidants tested herein. In the presence of PhIO, the oxidative profile of the manganese catalysts was very close to the oxidative profile of Fe(TFPP)Cl. However, in medium containing peroxide, the reactivity of the manganese catalysts was lower as compared to the reactivity of Fe(TFPP)Cl. Reactions with Fe(TFPP)Cl/oxidant systems were analyzed by UPLC-MS; up to thirteen compounds were detected. A7G oxidation catalyzed by Fe(TFPP)Cl yielded seven compounds. Three other compounds had m/z profile compatible with the profile of the A7G metabolites. The A7G oxidation assays performed in the presence of P450-bioinspired catalysts demonstrated their great catalytic potential toward A7G. The present results may be useful to many areas of knowledge and to the research and development of numerous chemical and phamarcological processes, especially in terms of drug design, biological assays, and applications in medicinal chemistry.
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      PubDate: 2017-02-21T16:04:25Z
      DOI: 10.1016/j.jinorgbio.2017.02.016
       
  • Ruthenium(II) piano stool coordination compounds with
           aminomethylphosphanes: Synthesis, characterisation and preliminary
           biological study in vitro
    • Authors: Michał Płotek; Radosław Starosta; Urszula K. Komarnicka; Agnieszka Skórska-Stania; Przemysław Kołoczek; Agnieszka Kyzioł
      Abstract: Publication date: Available online 20 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Michał Płotek, Radosław Starosta, Urszula K. Komarnicka, Agnieszka Skórska-Stania, Przemysław Kołoczek, Agnieszka Kyzioł
      Reaction of {[Ru(η6-p-cymene)Cl]2(μ-Cl)2} (1) with aminomethylphosphane derived from morpholine (P{CH2N(CH2CH2)2O}3 (A), PPh2{CH2N(CH2CH2)2O} (B)) or piperazine (P{CH2N(CH2CH2)2NCH2CH3}3 (C), PPh2{CH2N(CH2CH2)2NCH2CH3} (D)) results in four new piano stool ruthenium(II) coordination compounds: [Ru(η6-p-cymene)Cl2(A)] (2A), [Ru(η6-p-cymene)Cl2(B)] (2B), [Ru(η6-p-cymene)Cl2(C)] (2C) and [Ru(η6-p-cymene)Cl2(D)] (2D). Every complex was fully characterized using spectroscopic methods (1H, 13C{1H}, 31P{1H} NMR and ESI-MS), elemental analysis, X-ray single crystal diffraction and DFT calculations. Preliminary studies of in vitro cytotoxicity on the A549 (human lung adenocarcinoma) and MCF7 (human breast adenocarcinoma) cell lines revealed 2A–2D activity in the same order of magnitude as in the case of cisplatin. Additionally, the study confirmed the ability of 2A–2D to interact with DNA helix and transferrin.
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      PubDate: 2017-02-21T16:04:25Z
      DOI: 10.1016/j.jinorgbio.2017.02.017
       
  • Copper(II) interaction with the Human Prion 103–112 fragment –
           Coordination and oxidation
    • Authors: Gizella Csire; Lajos Nagy; Katalin Várnagy; Csilla Kállay
      Abstract: Publication date: Available online 20 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Gizella Csire, Lajos Nagy, Katalin Várnagy, Csilla Kállay
      The prion protein (PrP) is a membrane-anchored cell surface glycoprotein containing 231 amino acids. It has been associated with a group of neurodegenerative disorders. Copper(II) interaction with the Human Prion 103–112 fragment and its mutants has been studied with various techniques. The studied human prion fragment contains both histidine and methionine residues, while methionine residues are systematically replaced or displaced in the studied mutants. pH-potentiometric, UV–vis and circular spectroscopic techniques were applied to study the stoichiometry, stability and structure of the copper(II) complexes, while HPLC-MS and MS/MS were used for identifying the products of copper(II) catalyzed oxidation. The complex formation reactions of the studied ligands are rather similar; only 1:1 complexes are formed, where the imidazole nitrogen of the histidine residue is the main binding site beside the amide nitrogens of the peptide chain. The only difference is, that in the peptides which contain methionine in position 109, in addition to the (Nim,N−,N−) coordination mode, a weak interaction of thioether sulfur atoms can be supposed. The mutant peptide which does not contain methionine did not undergo oxidation, only the fragmentation of the peptide chain was perceived. However, in the case of methionine containing peptides, the peptide chain was not cleaved; but the oxidation of methionine to methionine sulfoxide occurred. Abbreviation Image 1 ACN acetonitrile CD circular dichroism spectroscopy dAKHA Ac-SKPKTNAKHA-NH2 dAKHM Ac-SKPKTNAKHM-NH2 DCM dichloromethane DIEA N,N-diisopropyl-ethylamine DIPEA N,N-diisopropylethylamine DMF N,N-dimethylmethanamide dM1AKHA Ac-MKPKTNAKHA-NH2 dMKHA Ac-SKPKTNMKHA-NH2 dMKHM Ac-SKPKTNMKHM-NH2 DODT 2,2′-(Ethylenedioxy)diethanethiol Fmoc Fluorenylmethyloxycarbonyl HOBt 1H-benzotriazol-1-ol Hu-PrPC cellular human prion protein MCO...
      PubDate: 2017-02-21T16:04:25Z
      DOI: 10.1016/j.jinorgbio.2017.02.018
       
  • Discerning the antioxidant mechanism of rapanone: A naturally occurring
           benzoquinone with iron complexing and radical scavenging activities
    • Authors: Karen de la Vega-Hernández; Manuel Antuch; Osmany Cuesta-Rubio; Yanier Núñez-Figueredo; Gilberto L Pardo-Andreu
      Abstract: Publication date: Available online 20 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Karen de la Vega-Hernández, Manuel Antuch, Osmany Cuesta-Rubio, Yanier Núñez-Figueredo, Gilberto L Pardo-Andreu
      Oxidative stress resulting from iron and reactive oxygen species (ROS) homeostasis breakdown has been implicated in several diseases. Therefore, molecules capable of binding iron and/or scavenging ROS may be reasonable strategies for protecting cells. Rapanone is a naturally occurring hydroxyl-benzoquinone with a privileged chelating structure. In this work, we addressed the antioxidant properties of rapanone concerning its iron-chelating and scavenging activities, and its protective potential against iron and tert-butyl hydroperoxide-induced damage to mitochondria. Experimental determinations revealed the formation of rapanone-Fe(II)/Fe(III) complexes. Additionally, the electrochemical assays indicated that rapanone oxidized Fe(II) and O2 − , thus inhibiting Fenton-Haber-Weiss reactions. Furthermore, rapanone displayed an increased 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability in the presence of Fe(II). The above results explained the capacity of rapanone to provide near-full protection against iron and tert-butyl hydroperoxide induced mitochondrial lipid peroxidation in energized organelles, which fail under non-energized condition. We postulate that rapanone affords protection against iron and reactive oxygen species by means of both iron chelating and iron-stimulated free radical scavenging activity.
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      PubDate: 2017-02-21T16:04:25Z
      DOI: 10.1016/j.jinorgbio.2017.02.019
       
  • Siderophore transport by MmpL5-MmpS5 protein complex in Mycobacterium
           tuberculosis
    • Authors: Padmani Sandhu; Yusuf Akhter
      Abstract: Publication date: Available online 14 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Padmani Sandhu, Yusuf Akhter
      Iron is an essential metal ion required for the various physiological activities of bacteria. The pathogenic bacteria remain dependent on the host cell for their iron requirements and evolved with specialized scavenging machinery in the form of iron chelating siderophores. Mycobacterium tuberculosis (Mtb) has two types of siderophore molecules, mycobactin and carboxymycobactin. These are synthesized inside bacterial cell and need to be transported outside by specialized membrane associated proteins. MmpL5-MmpS5 protein complex has been linked to the export of non-ferrated siderophores to extracellular environment but the precise molecular mechanism involved was largely unknown. We have investigated the association of MmpL5 with mycobactin synthesis and transport associated proteins using system wide protein-protein interaction network. Insights of mycobactin transport mechanism by MmpL5-MmpS5 complex was explored using docking and molecular dynamics simulations. The MmpL5 have association with many proteins which have reported role in iron acquisition or mycobactin biosynthesis. Mycobactin was docked into cytoplasmic and periplasmic binding sites. The molecular dynamics simulation analysis showed that at cytoplasmic binding site mycobactin could move towards the central channel of efflux pump and at periplasmic binding site towards the periplasm. MmpL5 was observed to carry out uptake of mycobactin from the cytoplasm and its release into the periplasmic space and MmpS5 was found to facilitate the periplasmic release of mycobactin and enhance the transport function of MmpL5. The mycobactin export is an attractive target for drug discovery and it could be done by inhibiting the MmpL5 protein's transport function.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.013
       
  • Proteome scale identification, classification and structural analysis of
           iron-binding proteins in bread wheat
    • Authors: Shailender Kumar Verma; Ankita Sharma; Padmani Sandhu; Neha Choudhary; Shailaja Sharma; Vishal Acharya; Yusuf Akhter
      Abstract: Publication date: Available online 14 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Shailender Kumar Verma, Ankita Sharma, Padmani Sandhu, Neha Choudhary, Shailaja Sharma, Vishal Acharya, Yusuf Akhter
      Bread wheat is one of the major staple foods of worldwide population and iron plays a significant role in growth and development of the plant. In this report, we are presenting the genome wide identification of iron-binding proteins in bread wheat. In the present study, the wheat genome derived putative proteome was screened for identification of iron-binding sequence motifs. Out of 602 putative iron-binding proteins, 130 were able to produce reliable structural models by homology techniques and further analyzed for the presence of iron-binding structural motifs. The computationally identified proteins appear to bind to ferrous and ferric ions and showed diverse coordination geometries. Glu, His, Asp and Cys amino acid residues were found to be mostly involved in iron binding. We have classified these proteins on the basis of their localization in the different cellular compartments. The identified proteins were further classified into their protein folds, families and functional classes ranging from structure maintenance of cellular components, regulation of gene expression, post translational modification, membrane proteins, enzymes, signaling and storage proteins. This comprehensive report regarding structural iron binding proteome provides useful insights into the diversity of iron binding proteins of wheat plants and further utilized to study their roles in plant growth, development and physiology.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.012
       
  • Disaggregation of human islet amyloid polypeptide fibril formation by
           ruthenium polypyridyl complexes
    • Authors: Dengsen Zhu; Gehui Gong; Wenji Wang; Weihong Du
      Abstract: Publication date: Available online 13 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Dengsen Zhu, Gehui Gong, Wenji Wang, Weihong Du
      The toxicity of amyloid proteins is associated with many degenerative and systematic diseases. The aggregation of human islet amyloid polypeptide may induce pancreatic β-cell death, which is linked to type II diabetes. Ruthenium complexes are inhibitors of various proteins and potential anticancer metallodrugs, which can also be used to disaggregate amyloid proteins. This work reported that several ruthenium polypyridyl complexes remarkably affected the peptide aggregation by predominant hydrophobic interaction and metal coordination, as reflected by thermodynamic parameters and mass spectrometry analysis. Morphology and particle size analysis showed that the amyloid fibrils were disaggregated from long fibrils into small nano particles. Addition of these complexes also decreased the cytotoxicity induced by the peptide. The results indicated that ruthenium polypyridyl complexes may be potential metallodrugs to treat amyloidosis.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.008
       
  • Structural and functional insights into corrinoid iron-sulfur protein from
           human pathogen Clostridium difficile
    • Authors: Yaozhu Wei; Xiaofei Zhu; Sixue Zhang; Xiangshi Tan
      Abstract: Publication date: Available online 13 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Yaozhu Wei, Xiaofei Zhu, Sixue Zhang, Xiangshi Tan
      The human pathogen Clostridium difficile infection (CDI) is one of the most important healthcare-associated infections. The Wood-Ljungdahl pathway, which is responsible for Acetyl-CoA biosynthesis, is essential for the survival of the pathogen and is absent in humans. The key proteins and enzymes involved in the pathway are attractive targets for the treatment of CDI. Corrinoid iron-sulfur protein (CoFeSP) is a key protein and acts as a methyl transformer in the Wood-Ljungdahl pathway. In this study, CoFeSP from Clostridium difficile (CoFeSPCd) was cloned, expressed in E. coli and characterized for the first time. The structure and function of CoFeSPCd were investigated using homology structure modeling, spectroscopy, electrochemistry, steady state/pre-steady state kinetics and molecular docking. The two metal centers of CoFeSPCd, corrinoid cofactor and [4Fe-4S] cluster, were characterized using metal analysis, structural modeling, UV–Vis, EPR and direct electrochemistry. The methyl transfer activity between CH3-H4folate (CH3-THF) and CoFeSPCd catalyzed by methyl transferase (MeTrCd) was determined by kinetic studies. These results provide a molecular basis for innovative drug design and development to treat human CDI.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.005
       
  • New Pt-NNSO core anticancer agents: Structural optimization and
           investigation of their anticancer activity
    • Authors: Shu Xian Chong; Yinxue Jin; Steve Chik Fun Au-Yeung; Kenneth Kin Wah To
      Abstract: Publication date: Available online 12 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Shu Xian Chong, Yinxue Jin, Steve Chik Fun Au-Yeung, Kenneth Kin Wah To
      A series of new platinum Pt(II) compounds possessing a bidentate leaving ligand modified from oxaliplatin has been synthesized, with one of the oxygen ligating atom substituted for a sulphur atom (resulting in a Pt-NNSO coordination core structure). The general structures are R,R-diaminocyclohexane (DACH)-Pt-(methylthio)acetic acid (K4) and DACH-Pt-(thiophenylacetic acid) (K4 derivatives). Substitution of an electron donating or withdrawing group at the ortho or para position on the phenyl ring of K4 derivatives was found to affect the complexes' stability, reactivity with the biological molecules (5′-guanosine monophosphate (5′-GMP) and L-methionine (L-Met)) and anticancer activity. 1H NMR experiments demonstrated that Pt-NNSO complexes formed a mixture of mono- and diadduct with 5′-GMP in various ratios, which are different from the classical Pt drugs (forming mainly diadduct). In addition, all of the K4 derivatives with improved lipophilicity are less deactivated by L-Met in comparison to cisplatin (CDDP) and oxaliplatin. Biological assessments showed that all Pt-NNSO complexes are less toxic than CDDP in normal porcine kidney cells and are minimally affected by drug resistance. Some of the new compounds also displayed comparable anticancer activity to CDDP or better than carboplatin in a few cancer cell lines. The lower reactivity of the Pt-NNSO compounds than CDDP towards thiol molecules, presumably leading to less efflux in resistant cancer cells, and the ability to inhibit autophagy were believed to allow the new compounds to be less affected by Pt resistance.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.002
       
  • Zinc complexes of diflunisal: Synthesis, characterization, structure,
           antioxidant activity, and in vitro and in silico study of the interaction
           with DNA and albumins
    • Authors: Alketa Tarushi; Chrisoula Kakoulidou; Catherine P. Raptopoulou; Vassilis Psycharis; Dimitris P. Kessissoglou; Ioanna Zoi; Athanasios N. Papadopoulos; George Psomas
      Abstract: Publication date: Available online 12 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Alketa Tarushi, Chrisoula Kakoulidou, Catherine P. Raptopoulou, Vassilis Psycharis, Dimitris P. Kessissoglou, Ioanna Zoi, Athanasios N. Papadopoulos, George Psomas
      From the reaction of ZnCl2 with the non-steroidal anti-inflammatory drug diflunisal (Hdifl), complex [Zn(difl-O)2(MeOH)4], 1 was formed, while in the presence of a N,N′-donor heterocyclic ligand 2,2′-bipyridylamine (bipyam), 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen) and 2,2′-dipyridylketone oxime (Hpko), the complexes [Zn(difl-O,O')2(bipyam)], 2, [Zn(difl-O,O′)2(bipy)], 3, [Zn(difl-O,O′)2(phen)], 4 and [Zn(difl-O)2(Hpko)2], 5 were isolated, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structures of complexes 2, 3 and 5 were determined by X-ray crystallography. The ability of the complexes to scavenge 1,1-diphenyl-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals and to inhibit soybean lipoxygenase was studied and the complexes were more active than free Hdifl. The interaction of the complexes with serum albumins was monitored by fluorescence emission spectroscopy and the corresponding binding constants were calculated. UV–vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were employed to investigate the interaction of the complexes with calf-thymus DNA and revealed intercalation as the most possible DNA-binding mode. Computational techniques were used to identify possible binding sites both albumins and DNA, and determine the druggability of human and bovine serum albumins with the five novel complexes. The majority of the complexes are stronger binders than the free Hdifl. This is the first study incorporating experimental and computational results to explore the binding activity of metal-NSAID complexes with DNA and serum albumins, suggesting their application as potential metallodrugs.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.010
       
  • Comparative study of hydrolytic and electron-driven processes in
           carboplatin biotransformation
    • Authors: Janina Kuduk-Jaworska; Jerzy J. Jański; Szczepan Roszak
      Abstract: Publication date: Available online 11 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Janina Kuduk-Jaworska, Jerzy J. Jański, Szczepan Roszak
      The results of computational simulation of reaction courses mimicking the transformation of carboplatin from pro-drug into its active shape, responsible for cytotoxic effect, are reported. Implementing the density functional theory (DFT) calculations and the supermolecular approach, we explored the pathways representing two disparate models of carboplatin bioactivation: (1) based on paradigm of carboplatin aquation, and (2) based on new hypothesis that transformation is controlled by electron-transfer processes. The calculated geometrical and thermodynamic parameters were used for evaluation of pathways. In contrast to carboplatin hydrolysis, representing a typical two stage SN2 mechanism, the postulated electron-driven reactions proceed under the dissociative electron attachment (DEA) mechanism. The reaction profiles predict endothermic effect in both stages of hydrolytic course and final exothermic effects for electron-driven processes. The most effective are hybrid processes including two-stages: water and subsequent electron impact on transformed carboplatin. The aqua-products, manifesting strong electron-affinity, can be the active form of drug capable to cytotoxic interaction with DNA, not only as alkylating agent but also as electron-acceptor. Concluding, the hybrid transformation of carboplatin is more favourable than hydrolytic.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.003
       
  • Synthetic investigation, physicochemical characterization and
           antibacterial evaluation of ternary Bi(III) systems with hydroxycarboxylic
           acid and aromatic chelator substrates
    • Authors: C.M. Nday; E. Halevas; A. Tsiaprazi-Stamou; D. Eleftheriadou; A. Hatzidimitriou; G. Jackson; D. Reid; A. Salifoglou
      Abstract: Publication date: Available online 11 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): C.M. Nday, E. Halevas, A. Tsiaprazi-Stamou, D. Eleftheriadou, A. Hatzidimitriou, G. Jackson, D. Reid, A. Salifoglou
      Due to its physical and chemical properties, bismuth (Bi(III)) is widely used in the treatment of several gastrointestinal and skin diseases, and infections caused by bacteria. Herein, its known antimicrobial potential was taken into consideration in the synthesis of two new hybrid ternary materials of Bi(III) with the physiological α-hydroxycarboxylic glycolic acid and 1,10-phenanthroline (phen), [Bi2(C2H2O3)2(C2H3O3)(NO3)]n .nH2O (1) and [Bi(C12H8N2)(NO3)4](C10H8N4) (2), aiming at improving its antibacterial properties. Their physicochemical characterization was carried out through elemental analysis, FT-IR, atomic absorption spectroscopy, single crystal X-ray diffraction, thermogravimetric analysis (TGA), photoluminescence, and 13C MAS-NMR techniques. The antimicrobial activity of the title complexes was directly linked to Bi(III) coordination environment and the incipient aqueous chemistry. For their antibacterial assessment, minimum inhibitory concentration (MIC), zone of inhibition (ZOI), and bacteriostatic-bacteriocidal activity were determined in various Gram positive (Staphylococcus aureus, Bacillus subtilis and Bacillus cereus) and Gram negative (Escherichia coli and Xanthomonas campestris) bacterial cultures, in reference to a positive control (ampicillin), encompassing further comparisons with literature data. The findings reveal that the new hybrid bismuth materials have significant antimicrobial effects against the employed bacteria. Specifically, 2 exhibits better antimicrobial properties than free Bi(NO3)3 and phen. On the other hand, 1 is bacteriostatic toward four microorganisms except X. campestris, with 2 being bacteriocidal toward four microorganisms except B. cereus. Collectively, the new hybrid, well-defined, and two of the rarely crystallographically characterized Bi(III) materials a) exhibit properties reflecting their composition and structure, and b) are expected to contribute to the development of efficient metallodrugs against drug-resistant bacterial infections.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.007
       
  • Aspartate aminotransferase is potently inhibited by copper complexes:
           Exploring copper complex-binding proteome
    • Authors: Yuqi Jia; Liping Lu; Caixia Yuan; Sisi Feng; Miaoli Zhu
      Abstract: Publication date: Available online 11 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Yuqi Jia, Liping Lu, Caixia Yuan, Sisi Feng, Miaoli Zhu
      Recent researches indicated that a copper complex-binding proteome that potently interacted with copper complexes and then influenced cellular metabolism may exist in organism. In order to explore the copper complex-binding proteome, a copper chelating ion-immobilized affinity chromatography (Cu-IMAC) column and mass spectrometry were used to separate and identify putative Cu-binding proteins in primary rat hepatocytes. A total of 97 putative Cu-binding proteins were isolated and identified. Five higher abundance proteins, aspartate aminotransferase (AST), malate dehydrogenase (MDH), catalase (CAT), calreticulin (CRT) and albumin (Alb) were further purified using a SP, and (or) Q-Sepharose Fast Flow column. The interaction between the purified proteins and selected 11 copper complexes and CuCl2 was investigated. The enzymes inhibition tests demonstrated that AST was potently inhibited by copper complexes while MDH and CAT were weakly inhibited. Schiff-based copper complexes 6 and 7 potently inhibited AST with the IC50 value of 3.6 and 7.2μM, respectively and exhibited better selectivity over MDH and CAT. Fluorescence titration results showed the two complexes tightly bound to AST with binding constant of 3.89×106 and 3.73×106 M−1, respectively and a stoichiometry ratio of 1:1. Copper complex 6 was able to enter into HepG2 cells and further inhibited intracellular AST activity.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.011
       
  • Interplay between autophagy and apoptosis in selenium deficient
           cardiomyocytes in chicken
    • Authors: Jie Yang; Yuan Zhang; Sattar Hamid; Jingzeng Cai; Qi Liu; Hao Li; Rihong Zhao; Hong Wang; Shiwen Xu; Ziwei Zhang
      Abstract: Publication date: Available online 10 February 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Jie Yang, Yuan Zhang, Sattar Hamid, Jingzeng Cai, Qi Liu, Hao Li, Rihong Zhao, Hong Wang, Shiwen Xu, Ziwei Zhang
      Dietary selenium (Se) deficiency can cause heart dysfunction, however the exact mechanism remains unclear. To understand this mechanism, 180day-old chicks, divided into two groups, C (control group) and L (low Se group), were fed with either a Se-sufficient (0.23mg/kg) or Se-deficient (0.033mg/kg) diets for 25days, respectively. Heart tissues and blood samples were collected. In L group, the activities of serum creatine kinase (CK) and creatine kinase-myoglobin (CK-MB) increased and typical ultrastructural apoptotic features were observed. Se deficiency up-regulated the mRNA levels of Cysteinyl aspartate specific proteinase 3 (Caspase-3), Cysteinyl aspartate specific proteinase 8 (Caspase-8), Cysteinyl aspartate specific proteinase 9 (Caspase-9), B cell lymphoma/leukemia 2 (Bcl-2), Bcl-2 Associated X Protein (Bax), (P <0.05), whereas, the mRNA levels of Microtubuleassociated protein light chains 3-1 (LC3-1), Autophagy associated gene 5 (ATG-5), Mammalian target of rapamycin (mTOR), Dynein and Becline-1 were down-regulated (P <0.05). Noticeably, Microtubuleassociated protein light chains 3-2 (LC3-2) mRNA level increased (P <0.05) by 20%. Western blot results showed that Se deficiency decreased the expression of Becline-1 and LC3-1 protein, however, the expression of Bax, Caspase-3 and Cysteinyl aspartate specific proteinase 12 (Caspase-12) increased at protein levels. The present study revealed that Se deficiency induced apoptosis while inhibited autophagy in chicken cardiomyocytes through Bax/Bcl-2 inhibition and caspases-mediated cleavage of Becline-1. Moreover, correlation analysis illustrates that apoptosis and autophagy might function contradictorily. Altogether we conclude that Se deficient chicken cardiomyocytes experienced apoptosis rather than autophagy which is considered to be more pro-survival.
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      PubDate: 2017-02-15T11:26:58Z
      DOI: 10.1016/j.jinorgbio.2017.02.006
       
  • Probing nitrite coordination in horseradish peroxidase by resonance Raman
           spectroscopy: Detection of two binding sites
    • Authors: Androulla Ioannou; Eftychia Pinakoulaki
      Abstract: Publication date: Available online 25 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Androulla Ioannou, Eftychia Pinakoulaki
      Nitrite is a powerful oxidant that affects the activity of peroxidases towards various substrates and leads to heme macrocycle modifications in members of the peroxidase family, such as the horseradish peroxidase (HRP). We have applied resonance Raman spectroscopy to investigate the structural properties of the species formed in the reaction of NO2 − with the ferric form of HRP. Our data demonstrate that the heme nitrovinyl group is partially formed at near neutral pH, without coordination of NO2 − to the heme Fe. Nitrite coordinates to the heme Fe at acidic pH in the nitro binding mode, characterized by the detection of the ν(Fe-NO2) at 563cm−1, δ(FeNO2) at 822cm−1 and νsym(NO2) at 1272cm−1. The sensitivity of the vibrations of the heme Fe-nitro complex to H/D exchange indicates H-bonding interaction of the heme-bound ligand with the distal environment that determines the NO2 − binding mode. A model describing the different modes of NO2 − binding in HRP is presented.
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      PubDate: 2017-01-28T01:05:19Z
      DOI: 10.1016/j.jinorgbio.2017.01.010
       
  • The Met80Ala and Tyr67His/Met80Ala mutants of human cytochrome c shed
           light on the reciprocal role of Met80 and Tyr67 in regulating ligand
           access into the heme pocket
    • Authors: Chiara Ciaccio; Lorenzo Tognaccini; Theo Battista; Manuela Cervelli; Barry D. Howes; Roberto Santucci; Massimo Coletta; Paolo Mariottini; Giulietta Smulevich; Laura Fiorucci
      Abstract: Publication date: Available online 24 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Chiara Ciaccio, Lorenzo Tognaccini, Theo Battista, Manuela Cervelli, Barry D. Howes, Roberto Santucci, Massimo Coletta, Paolo Mariottini, Giulietta Smulevich, Laura Fiorucci
      The spectroscopic and functional properties of the single Met80Ala and double Tyr67His/Met80Ala mutants of human cyt c have been investigated in their ferric and ferrous forms, and in the presence of different ligands, in order to clarify the reciprocal effect of these two residues in regulating the access of exogenous molecules into the heme pocket. In the ferric state, both mutants display an aquo high spin and a low spin species. The latter corresponds to an OH– ligand in Met80Ala but to a His in the double mutant. The existence of these two species is also reflected in the functional behavior of the mutants. The observation that (i) a significant peroxidase activity is present in the Met80Ala mutants, (ii) the substitution of the Tyr67 by His leads to only a slight increase of the peroxidase activity in the Tyr67His/Met80Ala double mutant with respect to WT, while the Tyr67His mutant behaves as WT, as previously reported, suggests that the peroxidase activity of cyt c is linked to an overall conformational change of the heme pocket and not only to the disappearance of the Fe-Met80 bond. Therefore, in human cyt c there is an interplay between the two residues at positions 67 and 80 that affects the conformation of the distal side of the heme pocket, and thus the sixth coordination of the heme.
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      PubDate: 2017-01-28T01:05:19Z
      DOI: 10.1016/j.jinorgbio.2017.01.008
       
  • Comparison of extracellular Cys/Trp motif between Schizosaccharomyces
           pombe Ctr4 and Ctr5
    • Authors: Mariko Okada; Takashi Miura; Takakazu Nakabayashi
      Abstract: Publication date: Available online 22 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Mariko Okada, Takashi Miura, Takakazu Nakabayashi
      The reduction and binding of copper ions to the Cys/Trp motif, which is characterized by two cysteines and two tryptophans, in the extracellular N-terminal domain of the copper transporter (Ctr) protein of fungi are investigated using the model peptides of Ctr4 and Ctr5 from Schizosaccharomyces pombe. The Cys/Trp motif of Ctr5 can reduce Cu(II) and ligate Cu(I), which is the same as that of Ctr4 previously reported. Titration of Cu(II) and Cu(I) ions indicates that both the Cys/Trp motifs of Ctr4 and Ctr5 reduce two Cu(II) and bind two Cu(I) per one peptide. However, the coordination structure of the Cu(I)-peptide complex differs between Ctr4 and Ctr5. Cu(I) is bound to the Cys/Trp motif of Ctr5 via cysteine thiolate-Cu(I) bonds and cation-π interaction with tryptophan, as reported for Ctr4, and a histidine residue in the Cys/Trp motif of Ctr5 is suggested to interact with Cu(I) via its Nτ atom. Ctr4 and Ctr5 exhibit a heterotrimeric form within cell membranes and the copper transport mechanism of the Ctr4/Ctr5 heterotrimer is discussed along with quantitative evaluation of the Cu(I)-binding constant of the Cys/Trp motif.
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      PubDate: 2017-01-28T01:05:19Z
      DOI: 10.1016/j.jinorgbio.2017.01.009
       
  • Crystal structure, cytotoxicity and action mechanism of Zn(II)/Mn(II)
           complexes with isoquinoline ligands
    • Authors: Feng-Yang Wang; Qian-Yu Xi; Ke-Bin Huang; Xiao-Ming Tang; Zhen-Feng Chen; Yan-Cheng Liu; Hong Liang
      Abstract: Publication date: Available online 6 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Feng-Yang Wang, Qian-Yu Xi, Ke-Bin Huang, Xiao-Ming Tang, Zhen-Feng Chen, Yan-Cheng Liu, Hong Liang
      Four μ2-Cl bridged dinuclear metal complexes with isoquinoline ligands, (MPDQ)2Zn2Cl4 (1) (MPDQ=4.5-methylenedioxy-1-pyridinedihydroisoquinoline), (PYP)2Zn2Cl4 (2) (PYP=5-pyridin-2-yl-[1,3]dioxolo[4,5-g]isoquinoline), (MPDQ)2Mn2Cl4 (3),and (PYP)2Mn2Cl4 (4) were synthesized and characterized. All complexes exhibited strong proliferation inhibition activity against various cancer cells. The underlying molecular mechanisms through which they caused the cancer cell death were also elucidated. Induction of apoptosis in MGC-803 cells by complex 2 was evidenced by annexin V+/PI− detection and DiD/DAPI staining assay. Further investigation revealed that complex 2 was able to induce intrinsic pathway-dependent apoptosis in cancer cells by triggering DNA damage which was caused by the overproduction of reactive oxygen species. Based on these studies, we suggest that Zn(II) complexes containing isoquinoline ligands can be developed as candidates for anti-cancer chemotherapeutics.
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      PubDate: 2017-01-13T22:45:42Z
      DOI: 10.1016/j.jinorgbio.2017.01.001
       
  • New insights into the reaction capabilities of His195 adjacent to the
           active site of nitrogenase
    • Authors: Ian Dance
      Abstract: Publication date: Available online 5 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Ian Dance
      The active site of the enzyme nitrogenase is FeMo-co, a C-centred Fe7MoS9 cluster, connected to the surrounding MoFe protein via ligands Cys275 and His442. Density functional calculations, involving 14 additional surrounding amino acids, focus on His195 because its mutation causes important reactivity changes, including almost complete loss of ability to reduce N2 to NH3. The Nε side-chain of His195 is capable of hydrogen bonding to S2B, bridging Fe2 and Fe6 of FeMo-co, believed to be the main reaction domain of nitrogenase. Details are presented for the possible ways in which protonated or deprotonated Nε of His195 interact with S2B or S2B-H or Fe2 or Fe2-H or Fe-(H2). Movements of the His195 side-chain allow formation of a significant short dihydrogen bond between Nε of His195 and H on Fe2: Nε-H••H-Fe2, with H–H=1.39Å. It is shown that a 180° rotation of the imidazole ring of His195 is not able to facilitate transfer of protons from the protein surface to FeMo-co. His195 is able to move H atoms to and from S2B, and the characteristics of H transfer between S2B and Nε of His195 are described, together with their dependence on the protonation state of His195 and the redox state of FeMo-co. The water molecule on the posterior Nδ side of His195 can mediate proton transfer to and from the side-chain of Tyr228. The accumulated results suggest that protonated His195 could be the agent for the first, most difficult, transfer of H to bound substrate N2.
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      PubDate: 2017-01-05T22:15:30Z
      DOI: 10.1016/j.jinorgbio.2017.01.005
       
  • Challenges encountered during development of Mn porphyrin-based, potent
           redox-active drug and superoxide dismutase mimic, MnTnBuOE-2-PyP5+, and
           its alkoxyalkyl analogues
    • Authors: Zrinka Rajic; Artak Tovmasyan; Otávio L. de Santana; Isabelle N. Peixoto; Ivan Spasojevic; Silmar A. do Monte; Elizete Ventura; Júlio S. Rebouças; Ines Batinic-Haberle
      Abstract: Publication date: Available online 5 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Zrinka Rajic, Artak Tovmasyan, Otávio L. de Santana, Isabelle N. Peixoto, Ivan Spasojevic, Silmar A. do Monte, Elizete Ventura, Júlio S. Rebouças, Ines Batinic-Haberle
      We disclose here the studies that preceded and guided the preparation of the metal-based, redox-active therapeutic Mn(III) meso-tetrakis(N-n-butoxyethylpyridyl)porphyrin, MnTnBuOE-2-PyP5+ (BMX-001), which is currently in Phase I/II Clinical Trials at Duke University as a radioprotector of normal tissue in cancer patients. N-substituted pyridylporphyrins are ligands for Mn(III) complexes that are among the most potent superoxide dismutase mimics thus far synthesized. To advance their design, thereby improving their physical and chemical properties and bioavailability/toxicity profiles, we undertook a systematic study on placing oxygen atoms into N-alkylpyridyl chains via alkoxyalkylation reaction. For the first time we show here the unforeseen structural rearrangement that happens during the alkoxyalkylation reaction by the corresponding tosylates. Comprehensive experimental and computational approaches were employed to solve the rearrangement mechanism involved in quaternization of pyridyl nitrogens, which, instead of a single product, led to a variety of mixed N-alkoxyalkylated and N-alkylated pyridylporphyrins. The rearrangement mechanism involves the formation of an intermediate alkyl oxonium cation in a chain-length-dependent manner, which subsequently drives differential kinetics and thermodynamics of competing N-alkoxyalkylation versus in situ N-alkylation. The use of numerous alkoxyalkyl tosylates, of different length of alkyl fragments adjacent to oxygen atom, allowed us to identify the set of alkyl fragments that would result in the synthesis of a single compound of high purity and excellent therapeutic potential.
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      PubDate: 2017-01-05T22:15:30Z
      DOI: 10.1016/j.jinorgbio.2017.01.003
       
  • Interaction of octahedral ruthenium(II) polypyridyl complex
           [Ru(bpy)2(PIP)]2+ with poly(U)•poly(A)*poly(U) triplex:increasing
           third-strand stabilization of the triplex without affecting the stability
           of the duplex
    • Authors: Zhiyuan Zhu; Mengna Peng; Jingwen Zhang; Lifeng Tan
      Abstract: Publication date: Available online 4 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Zhiyuan Zhu, Mengna Peng, Jingwen Zhang, Lifeng Tan
      Triple-helical RNA are of interest because of possible biological roles as well as the potential therapeutic uses of these structures, while the stability of triplexes is usually weaker than that of the Watson−Crick base pairing duplex strand due to the electrostatic repulsion between three polyanionic strands. Therefore, how to increase the stability of the specific sequences of triplexes are of importance. In this paper the binding of a Ru(II) complex, [Ru(bpy)2(PIP)]2+ (bpy = 2,2'-bipyridine, PIP = 2-phenyl-1H-imidazo[4,5-f]- [1,10]-phenanthroline), with poly(U).poly(A)*poly(U) triplex has been investigated by spectrophotometry, spectrofluorometry, viscosimetry and circular dichroism. The results suggest that [Ru(bpy)2(PIP)]2+ as a metallointercalator can stabilize poly(U)•poly(A)*poly(U) triplex (where • denotes the Watson-Crick base pairing and * denotes the Hoogsteen base pairing),while it stabilizes third-strand with no obvious effect on the duplex of poly(U)•poly(A), reflecting the binding of this complex with the triplex is favored by the Hoogsteen paired poly(U) third strand to a great extent.
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      PubDate: 2017-01-05T22:15:30Z
      DOI: 10.1016/j.jinorgbio.2017.01.004
       
  • Delineating hierarchy of selenotranscriptome expression and their response
           to selenium status in chicken central nervous system
    • Authors: Xiu-Qing Jiang; Chang-Yu Cao; Zhao-Yang Li; Wei Li; Cong Zhang; Jia Lin; Xue-Nan Li; Jing-Long Li
      Abstract: Publication date: Available online 4 January 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Xiu-Qing Jiang, Chang-Yu Cao, Zhao-Yang Li, Wei Li, Cong Zhang, Jia Lin, Xue-Nan Li, Jing-Long Li
      Selenium (Se) incorporated in selenoproteins as selenocysteine and supports various important cellular and organismal functions. We recently reported that chicken brain exhibited high priority for Se supply and retention under conditions of dietary Se deficiency and supernutrition Li et al. (2012) . However, the selenotranscriptome expressions and their response to Se status in chicken central nervous system (CNS) are unclear. To better understand the relationship of Se homeostasis and selenoproteins expression in chicken CNS, 1day-old HyLine White chickens were fed a low Se diet (Se-L, 0.028mg/g) supplemented with 4 levels of dietary Se (0 to 5.0mgSe/kg) as Na2SeO3 for 8weeks. Then chickens were dissected for getting the CNS, which included cerebral cortex, cerebellum, thalamus, bulbus cinereus and marrow. The expressions of selenoproteome which have 24 selenoproteins were detected by the quantitative real-time PCR array. The concept of a selenoprotein hierarchy was developed and the hierarchy of different regions in chicken CNS was existence, especially cerebral cortex and bulbus cinereus. The expression of selenoproteins has a hierarch while changing Se content, and Selenoprotein T (Selt), Selenoprotein K (Selk), Selenoprotein W (Selw), Selenoprotein U (Selu), Glutathione peroxidase 3 (Gpx3), Glutathione peroxidase 4 (Gpx4), Selenoprotein P (Sepp1), Selenoprotein O (Selo), Selenoprotein 15 (Sel15), Selenoprotein N (Seln), Glutathione peroxidase 2 (Gpx2) and Selenoprotein P 2 (Sepp2) take more necessary function in the chicken CNS. Therefore, we hypothesize that hierarchy of regulated the transcriptions of selenoproteome makes an important role of CNS Se metabolism and transport in birds.
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      PubDate: 2017-01-05T22:15:30Z
      DOI: 10.1016/j.jinorgbio.2017.01.002
       
  • New silver complexes with bioactive glycine and nicotinamide molecules –
           Characterization, DNA binding, antimicrobial and anticancer evaluation
    • Authors: Michaela Rendošová; Zuzana Vargová; Juraj Kuchár; Danica Sabolová; Štefan Levoča; Júlia Kudláčová; Helena Paulíková; Daniela Hudecová; Veronika Helebrandtová; Miroslav Almáši; Mária Vilková; Michal Dušek; Dáša Bobáľová
      Pages: 1 - 12
      Abstract: Publication date: March 2017
      Source:Journal of Inorganic Biochemistry, Volume 168
      Author(s): Michaela Rendošová, Zuzana Vargová, Juraj Kuchár, Danica Sabolová, Štefan Levoča, Júlia Kudláčová, Helena Paulíková, Daniela Hudecová, Veronika Helebrandtová, Miroslav Almáši, Mária Vilková, Michal Dušek, Dáša Bobáľová
      This study introduces a pair of newly synthesized silver complexes, [Ag2(HGly)2]n(NO3)2n (1) and [Ag(Nam)2]NO3·H2O (2) (Gly – glycine, Nam – nicotinamide), that were prepared and characterized by relevant methods in solid state (elemental, spectral, thermal and structural analysis) and their stability in solution was verified by 1H NMR measurements. Moreover, suitable reaction conditions were observed by potentiometry depending on pH in case of binary system Ag-Gly. X-ray analysis confirmed argentophilic interactions in complex 1 with an Ag1-Ag2 distance of 2.8018(6) Å. Antimicrobial testing indicates higher growth inhibition effect of complex 1 than complex 2. Moreover the effectivity of both complexes against bacteria (Staphylococcus aureus and Escherichia coli) is superior (or similar) to that of the commercially available Ag(I) sulfadiazine, AgSD (used, for example, in Dermazine cream). The binding of the Ag(I) complexes to calf thymus DNA was investigated using electronic absorption, fluorescence and circular dichroism spectrophotometry. The Stern–Volmer quenching constants obtained from the linear quenching plot were estimated in the range from 2.01×103 to 20.34×103 M−1. The results of topoisomerase I and topoisomerase II (Topo I and Topo II) inhibition assay suggested that complex 2 inhibits the enzyme activity of both enzymes at a concentration of 2μM. The cytotoxicity of both complexes on L1210 leukemia cells was revealed to be approximately three times higher than that of cisplatin. Moreover, the new Ag(I) complexes also induced apoptosis of the leukemia cells. The high DNA binding activity of these complexes is considered to be responsible for their cytotoxic effects.
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      PubDate: 2016-12-21T11:50:33Z
      DOI: 10.1016/j.jinorgbio.2016.12.003
      Issue No: Vol. 168 (2016)
       
  • Studies on the mechanism of action of antitumor bis(aminophenolate)
           ruthenium(III) complexes
    • Authors: Orsolya Dömötör; Rodrigo F.M. de Almeida; Leonor Côrte-Real; Cristina P. Matos; Fernanda Marques; António Matos; Carla Real; Tamás Kiss; Éva Anna Enyedy; M. Helena Garcia; Ana Isabel Tomaz
      Pages: 27 - 37
      Abstract: Publication date: March 2017
      Source:Journal of Inorganic Biochemistry, Volume 168
      Author(s): Orsolya Dömötör, Rodrigo F.M. de Almeida, Leonor Côrte-Real, Cristina P. Matos, Fernanda Marques, António Matos, Carla Real, Tamás Kiss, Éva Anna Enyedy, M. Helena Garcia, Ana Isabel Tomaz
      Two recently published Ru(III) complexes bearing (N2O2) tetradentate bis(aminophenolate) ligands, formulated as [Ru(III)(salan)(PPh3)Cl] (salan is the tetradentate ligand 6,6′-(1S,2S)-cyclohexane-1,2-diylbis(azanediyl)bis(methylene)bis(3-methoxyphenol) in complex 1, or 2,2′-(1S,2S)-cyclohexane-1,2-diylbis(azanediyl)bis(methylene)bis(4-methoxyphenol) in complex 2; PPh3 is triphenylphosphane) and found very active against ovarian and breast adenocarcinoma human cells were studied to outline their antitumor mode of action. The human cisplatin-sensitive ovarian adenocarcinoma line A2780 was used herein as the cell model. At a 24h challenge (similarly as found before for 72h) both complexes are active, their cytotoxicity being comparable to that of cisplatin in the same conditions. As a possible target in the cell for their action, the interaction of 1 and 2 with DNA was assessed through displacement of well-established DNA fluorescent probes (ethidium bromide, EB, and 4′,6-diamidino-2-phenylindole, DAPI) through steady-state and time-resolved fluorescence spectroscopy. The whole emission spectra were analyzed globally for the binary DNA–probe and ternary DNA–probe–Ru(III) complex systems. Both Ru(III) complexes can displace EB and bind to DNA with similar and moderate strong affinity with conditional stability constants of logK’=(5.05±0.01) for 1 and logK’=(4.79±0.01) for 2. The analysis of time-domain fluorescence intensity decays confirmed both qualitatively and quantitatively the model used to describe the binding and competition processes. Cell studies indicated that apoptosis is the major mechanism of cell death for both complexes, with 2 (the more active complex) promoting that process more efficiently than 1. Transmission electron micrographs revealed clear alterations on intracellular organization consistent with the induction of programmed cell death processes.
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      PubDate: 2016-12-21T11:50:33Z
      DOI: 10.1016/j.jinorgbio.2016.12.008
      Issue No: Vol. 168 (2016)
       
  • Potent Anticancer Activity of A New Bismuth (III) Complex against Human
           Lung Cancer Cells
    • Authors: Ruizhuo Ouyang; Yang Yang; Xiao Tong; Kai Feng; Yaoqin Yang; Huihong Tao; Xiaoshen Zhang; Tianyu Zong; Penghui Cao; Fei Xiong; Ning Guo; Yuhao Li; Yuqing Miao; Shuang Zhou
      Abstract: Publication date: Available online 11 December 2016
      Source:Journal of Inorganic Biochemistry
      Author(s): Ruizhuo Ouyang, Yang Yang, Xiao Tong, Kai Feng, Yaoqin Yang, Huihong Tao, Xiaoshen Zhang, Tianyu Zong, Penghui Cao, Fei Xiong, Ning Guo, Yuhao Li, Yuqing Miao, Shuang Zhou
      The aim of this work is experimental study of an interesting bismuth(III) complex derived from pentadentate 2.6-pyridinedicarboxaldehyde bis(4 N–methylthiosemicarbazone), [BiL(NO3)2]NO3 {L=2.6-pyridinedicarboxaldehyde bis(4N–methylthiosemicarbazone)}. A series of in vitro biological studies indicate that the newly prepared [BiL(NO3)2]NO3 greatly suppressed colony formation, migration and significantly induced apoptosis of human lung cancer cells A549 and H460, but did not obviously decrease the cell viability of non-cancerous human lung fibroblast (HLF) cell line, showing much higher anticancer activities than its parent ligands, especially with half maximum inhibitory concentration (IC50) <3.5μM. Moreover, in vivo study provides enough evidence that the treatment with [BiL(NO3)2]NO3 effectively inhibited A549 xenograft tumor growth on tumor-bearing mice (10mg/kg, tumor volume reduced by 97.92% and tumor weight lightened by 94.44% compared to control) and did not indicate harmful effect on mouse weight and liver. These results suggest that the coordination of free ligand with Bi(III) might be an interesting and potent strategy in the discovery of new anticancer drug candidates.
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      PubDate: 2016-12-13T11:25:07Z
      DOI: 10.1016/j.jinorgbio.2016.12.006
       
  • Synergistic antibacterial effect of Bi2S3 nanospheres combined with
           ineffective antibiotic gentamicin against methicillin-resistant
           Staphylococcus aureus
    • Authors: Lulu Ma; Jie Wu; Shilei Wang; Hao Yang; Donghui Liang; Zhong Lu
      Abstract: Publication date: Available online 10 December 2016
      Source:Journal of Inorganic Biochemistry
      Author(s): Lulu Ma, Jie Wu, Shilei Wang, Hao Yang, Donghui Liang, Zhong Lu
      In this paper, Bi2S3 nanospheres with size of 212nm were prepared by a simple hydrothermal process. The selectively enhanced antibacterial effects of Bi2S3 nanospheres with three classes of ineffective antibiotics, β-lactam (cefuroxime, CXM; cefotaxime, CTX and piperacillin, PIP), quinolone (ciprofloxacin, CIP) and aminoglycoside (gentamicin, GEN) against clinical isolated methicillin-resistant Staphylococcus aureus (MRSA) were investigated for the first time. GEN shows significantly synergistic growth inhibition against MRSA when combined with Bi2S3 nanospheres, while CXM, CTX, PIP and CIP do not. Raman spectroscopy and Z potential studies reveal that Bi2S3 could interact with GEN and the combination showed small electronegativity, which probably induced the increase of GEN content in cytoplasm of bacteria. Furthermore, the combination of Bi2S3 nanospheres and GEN can destroy the bacterial membrane function and induce more bactericidal reactive oxygen generation than that of Bi2S3 or GEN alone. The cytotoxicity test indicates that the combination of Bi2S3 and GEN presented low toxicity to human normal hepatocyte L02. This work shows that Bi2S3 nanospheres can be used to enhance the action of ineffective antibiotic GEN against MRSA, thus strengthening the antibiotic capacity for fighting MRSA infections.
      Graphical abstract image

      PubDate: 2016-12-13T11:25:07Z
      DOI: 10.1016/j.jinorgbio.2016.12.005
       
  • Silver complexes of ligands derived from adamantylamines : Water-soluble
           silver-donating compounds with antibacterial properties
    • Authors: Jorge Jimenez; Indranil Chakraborty; Mauricio Rojas-Andrade; Pradip K. Mascharak
      Abstract: Publication date: Available online 10 December 2016
      Source:Journal of Inorganic Biochemistry
      Author(s): Jorge Jimenez, Indranil Chakraborty, Mauricio Rojas-Andrade, Pradip K. Mascharak
      Two new silver(I) complexes, namely [Ag(qyAm)2](CF3SO3) (1) and [Ag(qyTAm)2](CF3SO3) (2), (qyAm =2-(quinonyl)iminoadamantane, qyTAm =2-(quinonyl)iminotriazaadamantane) have been synthesized and characterized by elemental analyses, 1H NMR, IR, electronic absorption spectroscopy, and X-ray diffraction. The coordination geometry of the silver center in both complexes is distorted tetrahedral where their respective qyAm and qyTAm ligand bind in a bidentate fashion using the imine and quinoline nitrogen atoms. Complex 2 is soluble in water and exhibits strong antimicrobial actions on both Gram-negative (E. coli, and P. aeruginosa) and Gram-positive (S. aureus) bacteria. The MIC values for complex 2 (4, 4, and 8μg for E. coli, P. aeruginosa, and S. aureus, respectively) are comparable to MIC values of silver nitrate and silver sulfadiazine.
      Graphical abstract image

      PubDate: 2016-12-13T11:25:07Z
      DOI: 10.1016/j.jinorgbio.2016.12.009
       
 
 
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