for Journals by Title or ISSN
for Articles by Keywords
Similar Journals
Journal Cover
Analytical Biochemistry
Journal Prestige (SJR): 0.633
Citation Impact (citeScore): 2
Number of Followers: 217  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0003-2697 - ISSN (Online) 1096-0309
Published by Elsevier Homepage  [3177 journals]
  • Development and validation of LC-ESI-MS/MS methods for quantification of
           27 free and conjugated estrogen-related metabolites
    • Abstract: Publication date: Available online 2 December 2019Source: Analytical BiochemistryAuthor(s): Carien van der Berg, Gerda Venter, Francois H. van der Westhuizen, Elardus ErasmusAn imbalance in the estrogen metabolism has been associated with an increased risk of breast cancer development. Evaluation of the estrogen biotransformation capacity requires monitoring of various estrogen metabolites. Up to now, only some estrogen metabolites could be measured in urine. However, in order to offer tailor made nutritional support or therapies, a complete estrogen metabolite profile is required in order to identify specific deficiencies in this pathway for each patient individually. Here, we focused on this need to quantify as many as possible of the estrogen-related metabolites excreted in urine. The method was developed to quantify 27 estrogen-related metabolites in small urine quantities. This entailed sample clean-up with a multi-step solid phase extraction procedure, derivatisation of the metabolites in the less water-soluble fraction through dansylation, and analyses using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The metabolites accurately quantified by the method devised included parent estrogens, hydroxylated and methylated forms, metabolites of the 16α-hydroxyestrogen pathway, sulphate and glucuronide conjugated forms, precursors and a related steroid hormone. This method was validated and enabled quantification in the high picograms and low nanograms per millilitre range. Finally, analyses of urine samples confirmed detection and quantification of each of the metabolites.Graphical abstractImage 1
  • Vinblastine production by the endophytic fungus Curvularia verruculosa and
           their in vitro cytotoxicity
    • Abstract: Publication date: Available online 30 November 2019Source: Analytical BiochemistryAuthor(s): Ramalingam Parthasarathy, Rajasree Shanmuganathan, Arivalagan PugazhendhiThe current study was to isolate endophytic fungi producing high yields of indole alkaloids such as vinblastine analogous to their host Cathranthus roseus. Endophytic fungi were isolated from the leaves of C. roseus, identified as Curvularia verruculosa by molecular techniques, the sequence was deposited in NCBI (MK995628). Vinblastine producing endophytic fungus was grown in 1L Vinca medium for 21 days. The extract was examined for vinblastine by chromatographic techniques. TLC plates showed purple colour spot co migrated with authentic vinblastine and Rf was calculated by HPTLC (Vin 1 vinblastine −0.75; authentic vinblastine-0.78), these results confirmed vinblastine presence in the Vin1 extract. Further, the TLC purified fungal extract was examined by LC-MS, which revealed the exact mass of vinblastine ([M + H]+ m/z 811.51). The most important of the study is high yield production of vinblastine; hence, the extract analysed by HPLC revealed 182 μg/L vinblastine. The TLC purified fungal vinblastine was analysed for the cytotoxicity effect on HeLa cell line and it depicted a higher activity with IC50-8.5 μg/mL and apoptotic morphological changes were analysed. All the results revealed that the endophytic fungus Curvularia verruculosa produced vinblastine and for the first time in a surplus amount compared to other fungi.Graphical abstractImage 1
  • Sensitivity of the polyDetect computational pipeline for phylogenetic
    • Abstract: Publication date: Available online 30 November 2019Source: Analytical BiochemistryAuthor(s): Jessica M. Storer, Jerilyn A. Walker, Vallmer E. Jordan, Mark A. BatzerAlu elements are powerful phylogenetic markers. The combination of a recently-developed computational pipeline, polyDetect, with high copy number Alu insertions has previously been utilized to help resolve the Papio baboon phylogeny with high statistical support. Here, the polyDetect method was applied to the highly contentious Cebidae phylogeny within New World monkeys (NWM). The polyDetect method relies on conserved homology/identity of short read sequence data among the species being compared to accurately map predicted shared Alu insertions to each unique flanking sequence. The results of this comprehensive assessment indicate that there were insufficient sequence homology/identity stretches in non-repeated DNA sequences among the four Cebidae genera analyzed in this study to make this strategy phylogenetically viable. The ∼20 million years of evolutionary divergence of the Cebidae genera has resulted in random sequence decay within the short read data, obscuring potentially orthologous elements in the species tested. These analyses suggest that the polyDetect pipeline is best suited to resolving phylogenies of more recently diverged lineages when high-quality assembled genomes are not available for the taxa of interest.Graphical abstractImage 1
  • Application of near-infrared spectroscopy and class-modeling to antibiotic
    • Abstract: Publication date: Available online 28 November 2019Source: Analytical BiochemistryAuthor(s): Hui Chen, Zan Lin, Chao TanNowadays, counterfeit medicines have become very popular due to the extension of the Internet. Broad-spectrum antibiotics with similar effect, but different prices, provide a gold opportunity for illegal traders to counterfeit. It is found that some genuine packaging of expensive brand drugs are recycled and then used to refill other kinds of cheap antibiotic tablets. It is of great importance to establish an effective antibiotic authentication method to check whether a product with a specific claim on its label is compatible with that declaration. In the present work, the feasibility of near-infrared (NIR) spectroscopy coupled with class-modeling for antibiotics authentication, i.e., counterfeiting between different antibiotics, is investigated. A total of 591 antibiotics samples of nine classes of different dosage forms were collected. Principal component analysis (PCA) was used for exploratory analysis. An effective model-independent filter method, i.e., relief, was used for feature selection and a novel class-modeling algorithm was used to construct authentication models. Three kinds of antibiotics were used as the target classes for experiments. The results confirmed that such a scheme is feasible and can be used in the screening of fake drug.Graphical abstractImage 1
  • Highly effective methods for expression/purification of recombinant human
           HSP90 and its four distinct (N-LR-M-C) domains
    • Abstract: Publication date: Available online 28 November 2019Source: Analytical BiochemistryAuthor(s): Siripat Aluksanasuwan, Paleerath Peerapen, Sirikanya Plumworasawat, Juthatip Manissorn, Visith ThongboonkerdHeat shock protein 90 (HSP90) plays essential roles in the normal physiology and comprises four distinct domains, including NH2-terminal (N), charged linker region (LR), middle (M), and COOH-terminal (C) domains, all of which regulate HSP90 biological functions. We reported herein detailed protocols to produce recombinant full-length (FL) and all these four domains of human HSP90 from Escherichia coli. cDNAs encoding FL, N, LR, M and C domains of human HSP90α were amplified and cloned into pET-32b(+) expression vector. All HSP90 constructs were expressed as soluble Trx-His-S tagged proteins after induction with 0.25 mM isopropyl-β-d-thiogalactopyranoside (IPTG) at 18 °C overnight and further purified by affinity chromatography using nickel-nitrilotriacetic acid (Ni-NTA) resin. The enterokinase (EK) digestion was optimized for efficient cleavage of the Trx-His-S tag from each HSP90 construct by varying concentrations of EK (0.5–1 U) and urea (0–3 M). Each HSP90 construct was highly purified and approximately 0.1–1 mg proteins were obtained from 100 ml of bacterial culture. All the purified HSP90 constructs were successfully confirmed by tandem mass spectrometry (nanoLC-ESI-ETD MS/MS) and their secondary structure was quantified using attenuated total reflection – Fourier-transform infrared (ATR-FTIR) spectroscopy. Our expression and purification protocols would facilitate further structural and functional studies of human HSP90.Graphical abstractImage 1
  • Assessment of expression and specific activities of transglutaminases TG1,
           TG2 and FXIII-A during osteoclastogenesis
    • Abstract: Publication date: Available online 28 November 2019Source: Analytical BiochemistryAuthor(s): H. Sun, M.T. KaartinenOsteoclasts are large multinucleated bone-resorbing cells derived from monocyte/macrophage lineage. Macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) drive the multi-stage osteoclastogenesis. Transglutaminases (TGs) are Ca2+- and thiol-dependent acyl transferases and protein crosslinking enzymes. TG enzyme family contains eight catalytically active enzymes TG1-7 and Factor XIII-A (FXIII-A). Recent studies have shown that TG1, TG2, and FXIII-A are present in osteoclasts and that TG2 and FXIII-A regulate osteoclastogenesis. In this study, we examined gene and protein expression and specific activities of TG1, TG2 and FXIII-A during osteoclastogenesis using “Hitomi peptides” in a day-by-day manner. We report that TGs activities are highest in the differentiation and early fusion phases and then decrease dramatically. TGs activities were upregulated by M-CSF and downregulated by addition of RANKL. FXIII-A was dramatically downregulated by RANKL, suggesting its involvement in M–CSF–mediated precursor commitment phase. TG1 and TG2 proteins were present throughout osteoclastogenesis, suggesting that they may have functions in both differentiation and fusion. In summary, the three TGs likely exert distinct functions at different stages of osteoclastogenesis. Our work also demonstrates that the “Hitomi peptides” are highly specific tools for detection of distinct TGs in a system where multiple TGs are present.Graphical abstractImage 1
  • Does interaction of monoclonal antibody charge variants with VEGF-A and
           ELISA reagents affect its quantification'
    • Abstract: Publication date: Available online 27 November 2019Source: Analytical BiochemistryAuthor(s): Shravan Sreenivasan, Deepak Kumar, Himanshu Malani, Anurag S. RathoreAbstractThe ability of an enzyme linked immunosorbent assay (ELISA) to measure the concentration of charge variants of a monoclonal antibody (mAb) biotherapeutic has been investigated. Percentage recovery was found to be in the range of 80%–120% with inter and intra assay variation between 5% and 15%. Linear regression analysis of ELISA output at different dilutions yielded a good fit (R2 > 0.98). Assay output was not hindered by the presence of serum proteins and other analytes such as GCSF, demonstrating acceptable precision and specificity. It was concluded that the charge variants of the mAb can be accurately quantified by ELISA.
  • Asymmetric mutant-enriched polymerase chain reaction and quantitative DNA
           melting analysis of KRAS mutation in colorectal cancer
    • Abstract: Publication date: Available online 26 November 2019Source: Analytical BiochemistryAuthor(s): Irina V. Botezatu, Valentina N. Kondratova, Valery P. Shelepov, Natalia N. Mazurenko, Irina V. Tsyganova, Olga Yu Susova, Anatoly V. LichtensteinIdentification of mutant genes in tumor tissues and blood plasma (solid and liquid biopsy samples, respectively) is a necessity for individualized treatment of cancer patients. Here we report the use of a novel mutant-enriched PCR - quantitative DNA melting curve analysis (mePCR-qDMA) with TaqMan probes. The TaqMan probes served as blocking agents during PCR and as hybridization probes during DNA melting curve analyses. The end-point measurement of melt peaks areas by PeakFit software, a nonlinear iterative curve-fitting program, permitted quantification of the mutant/wild-type allele ratios. Approximately 6% and 0.1% of mutant KRAS allele in an excess of wild-type allele is detected with the standard and mePCR-qDMA processes, respectively. The application of the approach was tested for detecting the KRAS codon 12/13 mutation in paired tumor and blood plasma samples from 20 colorectal cancer patients. KRAS mutants were detected in 7 and 18 FFPE tumor samples, and in 3 and 7 plasma samples by the standard and mePCR-qDMA process, respectively. The results were confirmed by Sanger sequencing. This simple, rapid, cost-effective, and quantitative method carried out in a closed-tube format could be applied for the clinical analyses of other cancer genes.Graphical abstractImage 1
  • p-Aminobenzoic acid as an alternative chemical biopsy agent for
           human hepatic UDP-glucose
    • Abstract: Publication date: Available online 21 November 2019Source: Analytical BiochemistryAuthor(s): Cristina Barosa, Harshitha Shanmugam, Fernando Cabral, John G. JonesAbstractp-Aminobenzoic acid (PABA) was evaluated for noninvasive sampling of UDP-glucose in the liver. Six healthy subjects ingested 550 mg PABA during a breakfast meal. Urine was collected 0–2 and 2–4 h after PABA ingestion. N-acetyl PABA glucuronide (NAPG) was identified with 522 ± 212 μmol recovered in the 2–4 h urines. One of the subjects ingested 2 g of 98% [U–2H7]glucose alongside PABA and the NAPG was analyzed for positional 2H-enrichment by 2H NMR following derivatization to 5-O-acetyl monoacetone glucuronolactone. In conclusion, PABA is an effective agent for the chemical biopsy of hepatic UDP-glucose in humans.
  • A flexible, robust microbead-based assay for quantification and
           normalization of target protein concentrations
    • Abstract: Publication date: Available online 20 November 2019Source: Analytical BiochemistryAuthor(s): Eric J. Snider, Alexandra R. Crowley, Julia Raykin, R. Kijoon Kim, Fiona Splaine, C. Ross EthierAlthough there are many methods for quantifying the concentration of specific proteins in samples, current techniques are technically challenging or do not easily lend themselves to normalization. Here, we describe a microbead-based assay for quantifying specific protein concentration(s) that is high-throughput, inexpensive, simple-to-use, and intrinsically incorporates normalization against the sample total protein content. This assay, termed the FRANC assay, exploits high affinity biotin-streptavidin binding to couple sample proteins to streptavidin-labelled magnetic microbeads. Proteins are then antibody-probed, followed by labeling of proteins on the microbead with fluorescent dye, and flow cytometry-based analysis. The FRANC assay demonstrates detection limits for target proteins in the femtogram range, with a linear range up to as much as 10 ng. Normalization of target protein concentrations resulted in an 80% reduction in variability as compared to non-normalized measurements. We conclude that the FRANC assay offers attractive advantages over current methods for quantifying specific protein(s) in samples.Graphical abstractImage 1
  • Freeze-drying enables homogeneous and stable sample preparation for
           determination of fecal short-chain fatty acids
    • Abstract: Publication date: Available online 18 November 2019Source: Analytical BiochemistryAuthor(s): Jun Ueyama, Masaya Oda, Masaaki Hirayama, Kuniyo Sugitate, Norihiro Sakui, Risa Hamada, Mikako Ito, Isao Saito, Kinji OhnoBackgroundThe analysis methods for fecal short-chain fatty acids (SCFAs) have evolved considerably. Recently, the role of SCFAs in gastrointestinal physiology and their association with intestinal microbiota and disease were reported. However, the intra-fecal variability and storage stability of SCFAs have not been extensively investigated. The aim of this study was to understand the limitations of the measurement of SCFAs in crude feces and develop a useful pre-examination procedure using the freeze-drying technique.MethodsSCFAs in crude feces, obtained from healthy volunteers, and freeze-dried feces were determined by derivatization with isobutyl chloroformate, followed by liquid–liquid extraction with hexane, and separation and analysis using gas chromatography–mass spectrometry.ResultsAmong the SCFAS, the maximum intra-fecal variability was observed for iso-butyrate (coefficient of variation of 37.7%), but the freeze-drying procedure reduced this variability (coefficient of variation of 7.9%). Similar improvements were also observed for other SCFAs. Furthermore, significant decreases in the SCFA amounts were observed with storage at 4 °C for 24 h.ConclusionsThe freeze-drying procedure affords fecal SCFA stability, even with storage at room temperature for 3 d. The freeze-drying procedure allows reliable SCFA measurements without labour-intensive processes. Therefore, the freeze-drying procedure can be applied in basic, clinical, and epidemiological studies.Graphical abstractImage 1
  • Rapid and reliable HILIC-MS/MS method for monitoring allantoin as a
           biomarker of oxidative stress
    • Abstract: Publication date: Available online 17 November 2019Source: Analytical BiochemistryAuthor(s): Petr Kozlik, Lenka Hasikova, Blanka Stiburkova, Jakub Zavada, Kveta KalikovaAllantoin is an excellent biomarker of oxidative stress in humans as the main product of uric acid oxidation by reactive oxygen species. Yet, allantoin determination is still not routinely performed in clinical laboratories. Therefore, we developed a fast, simple, selective, and sensitive UHPLC-MS/MS method for allantoin determination in human serum using an isotopically labeled internal standard. Our analytical protocol provided high sensitivity by mass spectrometry detection and high throughput by HILIC-MS/MS analysis within 4 min, with one-step serum sample preparation approximately within 7 min. Lastly, our protocol was fully validated to demonstrate its reliability in allantoin determination in human serum. The method showed an excellent linear range from 0.05 to 100 μM, with precision ranging from 1.8 to 11.3% (RSD), and with accuracy (relative error %) within ±6.0%. The method was then applied to analyze the concentration of allantoin in serum samples from 71 patients with chronic gout without treatment with xanthine oxidase inhibitors. The median serum allantoin concentration in the cohort was 2.8 μM (n = 71). Overall, our simple analytical protocol has the potential to be easily implemented in clinical routine practice for monitoring allantoin as a key oxidative stress biomarker.Graphical abstractImage 1
  • Prediction of drug-target interaction based on protein features using
           undersampling and feature selection techniques with boosting
    • Abstract: Publication date: Available online 15 November 2019Source: Analytical BiochemistryAuthor(s): S.M. Hasan Mahmud, Wenyu Chen, Han Meng, Hosney Jahan, Yougsheng Liu, S.M. Mamun HasanAccurate identification of drug-target interaction (DTI) is a crucial and challenging task in the drug discovery process, having enormous benefit to the patients and pharmaceutical company. The traditional wet-lab experiments of DTI is expensive, time-consuming, and labor-intensive. Therefore, many computational techniques have been established for this purpose; although a huge number of interactions are still undiscovered. Here, we present pdti-EssB, a new computational model for identification of DTI using protein sequence and drug molecular structure. More specifically, each drug molecule is transformed as the molecular substructure fingerprint. For a protein sequence, different descriptors are utilized to represent its evolutionary, sequence, and structural information. Besides, our proposed method uses data balancing techniques to handle the imbalance problem and applies a novel feature eliminator to extract the best optimal features for accurate prediction. In this paper, four classes of DTI benchmark datasets are used to construct a predictive model with XGBoost. Here, the auROC is utilized as an evaluation metric to compare the performance of pdti-EssB method with recent methods, applying five-fold cross-validation. Finally, the experimental results indicate that our proposed method is able to outperform other approaches in predicting DTI, and introduces new drug-target interaction samples based on prediction probability scores. pdti-EssB webserver is available online at abstractImage 1
  • Cytological examination of cerebrospinal fluid: Sysmex UF-1000i versus
           optical microscopy
    • Abstract: Publication date: Available online 5 November 2019Source: Analytical BiochemistryAuthor(s): A. Maleb, O. Bouayadi, J. El Malki, S. Rifai, S. Lamrabat, E. Benaissa, Y. Ben Lahlou, M. Frikh, M. ElouennassAbstractWe evaluated the body fluid module on Sysmex UF-1000i (UF-1000i-BF) for analysis of white blood cell (WBC) and red blood cell (RBC) in cerebrospinal fluid.We collected 93 cerebrospinal fluid samples and compared the results of the UF-1000i-BF mode with the Fast-Read 102 disposable counting cell.Results shows a good correlation between the UF-1000i and the microscopic examination. The concordance percentage is 99.06% for white blood cells and 85.18% for red blood cells.The UF-1000i-BF mode offers rapid and reliable total WBC and RBC counts for initial screening of cerebrospinal fluid, and can improve the workflow in a routine laboratory.
  • Carboxymethylcellulose enhances the production of single-stranded DNA
           aptamers generated by asymmetric PCR
    • Abstract: Publication date: Available online 5 November 2019Source: Analytical BiochemistryAuthor(s): Oleksij Redcenko, Lubica Draberova, Petr DraberNucleic acid aptamers are single-stranded (ss)DNA or RNA oligonucleotides that can take various conformations and bind specifically and with high affinity to selected targets. While the introduction of SELEX (systematic evolution of ligands by exponential enrichment) revolutionized the production of the aptamers, this procedure is impeded by the formation of undesirable by-products reflecting hybridization among complementary oligonucleotides in the ssDNA libraries during asymmetric PCR. To reduce nonspecific amplification we tested cellulose-derived compounds and found that sodium carboxymethylcellulose (CMC) at a concentration 0.05%–0.2% efficiently suppressed production of undesirable large DNA amplicons during asymmetric PCR in the course of SELEX. Formation of the PCR by-products was reduced by CMCs of low and medium viscosity more than by CMCs of high viscosity, and all of them bound to DNA oligonucleotides as determined by electrophoresis in agarose gels. In contrast to CMC, methylcellulose did not reduce the formation of the PCR by-products and did not bind to DNA. DNA aptamers selected in the presence of CMC could be used directly in enzyme-linked immunosorbent-like assay. The combined data suggest that CMC binds weekly to DNA oligonucleotides through hydroxyl groups and in this way inhibits low-affinity DNA-DNA hybridization and enhances the production of specific amplicons in asymmetric PCR.Graphical abstractImage 1
  • SDBP-Pred: Prediction of single-stranded and double-stranded DNA-binding
           proteins by extending consensus sequence and K-segmentation strategies
           into PSSM
    • Abstract: Publication date: Available online 3 November 2019Source: Analytical BiochemistryAuthor(s): Farman Ali, Muhammad Arif, Zaheer Ullah Khan, Muhammad Kabir, Saeed Ahmed, Dong-Jun YuIdentification of DNA-binding proteins (DNA-BPs) is a hot issue in protein science due to its key role in various biological processes. These processes are highly concerned with DNA-binding protein types. DNA-BPs are classified into single-stranded DNA-binding proteins (SSBs) and double-stranded DNA-binding proteins (DSBs). SSBs mainly involved in DNA recombination, replication, and repair, while DSBs regulate transcription process, DNA cleavage, and chromosome packaging. In spite of the aforementioned significance, few methods have been proposed for discrimination of SSBs and DSBs. Therefore, more predictors with favorable performance are indispensable. In this work, we present an innovative predictor, called SDBP-Pred with a novel feature descriptor, named consensus sequence-based K-segmentation position-specific scoring matrix (CSKS-PSSM). We encoded the local discriminative features concealed in PSSM via K-segmentation strategy and the global potential features by applying the notion of the consensus sequence. The obtained feature vector then input to support vector machine (SVM) with linear, sigmoid and radial base function (RBF) kernels. Our model with SVM-RBF achieved the highest accuracies on three tests namely jackknife, 10-fold, and independent tests, respectively than the recent method. The obtained prediction results illustrate the superlative prediction performance of SDBP-Pred over existing studies in the literature so far.Graphical abstractA novel sequence-based predictor, called SDBP-Pred is designed for discrimination of single-stranded DNA-binding proteins (SSBs) and double-stranded DNA-binding proteins (DSBs). The features are extracted by descriptor, named consensus sequence-based K-segmentation position-specific scoring matrix (CSKS-PSSM) and the classification is performed with support vector machine.Image 1
  • Important methodological aspects that should be taken into account during
           the research of isolated mitochondria
    • Abstract: Publication date: Available online 1 November 2019Source: Analytical BiochemistryAuthor(s): Dairo A. RendonAbstractIsolated mitochondria have been widely used for the study of energetic functioning of these important cellular organelles in a physiological or pathophysiological state. This is due, on the one part, to the fact that isolated mitochondria are relatively easy to isolate from a great variety of animal tissues, and on the other part to the fact that their energetic functioning is relatively easy to study experimentally. Nevertheless, they have a great disadvantage because of the fact that these biological structures can easily undergo structural-functional changes during their in vitro handling, causing many conclusions reported in the research of isolated mitochondria to be merely the fruit of experimental artifacts. The present review describes a series of important methodological aspects that should be taken into account in order to obtain reliable results in the study of the energetic functioning (and of other aspects) of isolated mitochondria.
  • A sensitive H2O2 biosensor based on carbon nanotubes/tetrathiafulvalene
           and its application in detecting NADH
    • Abstract: Publication date: Available online 1 November 2019Source: Analytical BiochemistryAuthor(s): Xingcan Huang, Jiru Zhang, Lili Zhang, Hang Su, Xiumei Liu, Jian LiuReduced nicotinamide adenine dinucleotide (NADH) plays a pivotal role in the electron-transfer chain of biological system. Analysis of many biological markers is based on the detection of the enzymatically generated NADH. In this paper, a sensitive hydrogen peroxide (H2O2) biosensor, fabricated by carbon nanotubes (CNTs)/tetrathiafulvalene (TTF)/horseradish peroxidase (HRP), was applied for detecting the NADH in a buffer containing methylene blue (MB) at low operating potential of - 0.3 V (vs. Ag/AgCl). Since the NADH could be oxidized by MB to release H2O2, the electrochemical biosensor enables to detect the NADH in the MB buffer. And the low working potential made the biosensor avoid the interference from other electroactive substances. Linear response ranges from 10 μM to 790 μM, with a sensitivity of 4.76 μA mM−1 and a detection limit of 1.53 μM were obtained under the optimum conditions. The proposed sensor provided a promising approach for sensitively detecting the NADH.Graphical abstractImage 1
  • In vitro selection of anti-gliadin single-domain antibodies from a na├»ve
           library for cDNA-display mediated immuno-PCR
    • Abstract: Publication date: Available online 31 October 2019Source: Analytical BiochemistryAuthor(s): Chathuni Jayathlake, Shigefumi Kumachi, Hidenao Arai, Maiko Motohashi, Takuya Terai, Akikazu Murakami, Naoto NemotoGluten intolerance, or adverse intestinal reactions to gluten, is a fairly common problem among certain groups of people. Celiac disease is the most severe form of gluten intolerance, which can lead to permanent damage in the digestive system. Since lifelong avoidance of gluten is the only available treatment, development of reliable techniques to identify gluten contamination in food is important. Gliadin, a component of gluten, is known to play a major role in gluten toxicity. In this study, cDNA display method was used to select specific single-domain antibodies against toxic gliadin from an alpaca-derived naïve VHH library. The cDNA display method is a promising in vitro display technique, which uniquely converts an unstable mRNA-protein fusion molecule to a stable mRNA/cDNA-protein fusion molecule using a well-designed puromycin linker. Three candidate VHHs were selected and the affinities of the VHHs were observed by pulldown assay and indirect ELISA method. In addition, a novel cDNA display mediated immuno-PCR method (cD-IPCR) was successfully applied to detect gliadin in food. We believe this work demonstrates the potential application of the cDNA display method in selecting binders against toxic and heterogeneous targets such as gliadin with an immunization-free preparation manner.Graphical abstractImage 1
  • VHH characterization.Recombinant VHHs: Production, characterization and
    • Abstract: Publication date: Available online 30 October 2019Source: Analytical BiochemistryAuthor(s): Eric Chabrol, Johann Stojko, Alexandre Nicolas, Thomas Botzanowski, Benjamin Fould, Mathias Antoine, Sarah Cianférani, Gilles Ferry, Jean A. BoutinAmong the biological approaches to therapeutics, are the cells, such as CAR-T cells engineered or not, the antibodies armed or not, and the smaller protein scaffolds that can be modified to render them specific of other proteins, à la façon of antibodies. For several years, we explored ways to substitute antibodies by nanobodies (also known as VHHs), the smallest recognizing part of camelids’ heavy-chain antibodies: production of those small proteins in host microorganisms, minute analyses, characterization, and qualification of their affinity towards designed targets. Here, we present three standard VHHs described in the literature: anti-albumin, anti-EGF receptor and anti-HER2, a typical cancer cell surface -associated protein. Because they differ slightly in global structure, they are good models to assess our body of analytical methodologies. The VHHs were expressed in several bacteria strains in order to identify and overcome the bottlenecks to obtain homogeneous preparations of this protein. A large panel of biophysical tools, ranging from spectroscopy to mass spectrometry, was here combined to assess VHH structural features and the impact of the disulfide bond. The routes are now ready to move to more complex VHHs raised against specific targets in numerous areas including oncology.Graphical abstractImage 1
  • Rapid and sensitive detection of Salmonella with reduced graphene
           oxide-carbon nanotube based electrochemical aptasensor
    • Abstract: Publication date: Available online 23 October 2019Source: Analytical BiochemistryAuthor(s): Jimmy Nelson Appaturi, Thiruchelvi Pulingam, Kwai Lin Thong, Shalini Muniandy, Noraini Ahmad, Bey Fen LeoRapid detection of foodborne pathogens is crucial as ingestion of contaminated food products may endanger human health. Thus, the objective of this study was to develop a biosensor using reduced graphene oxide-carbon nanotubes (rGO-CNT) nanocomposite via the hydrothermal method for accurate and rapid label-free electrochemical detection of pathogenic bacteria such as Salmonella enterica. The rGO-CNT nanocomposite was characterized using Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction and transmission electron microscopy. The nanocomposite was dropped cast on the glassy carbon electrode and further modified with amino-modified DNA aptamer. The resultant ssDNA/rGO-CNT/GCE aptasensor was then used to detect bacteria by using differential pulse voltammetry (DPV) technique. Synergistic effects of aptasensor was evident through the combination of enhanced electrical properties and facile chemical functionality of both rGO and CNT for the stable interface. Under optimal experimental conditions, the aptasensor could detect S. Typhimurium in a wide linear dynamic range from 101 until 108 cfu mL−1 with a 101 cfu mL−1 of the limit of detection. This aptasensor also showed good sensitivity, selectivity and specificity for the detection of microorganisms. Furthermore, we have successfully applied the aptasensor for S. Typhimurium detection in real food samples.Graphical abstractImage 1
  • Carbon dots derived from pea for specifically binding with
           Cryptococcus neoformans
    • Abstract: Publication date: Available online 20 October 2019Source: Analytical BiochemistryAuthor(s): Qian Su, Chunsong Lu, Jie Liu, Xiaoming YangHerein, we have prepared two kinds of carbon dots (CDs) on the basis of pea (p-CDs) and sesame (s-CDs) through a facile hydrothermal way. Basically, the two CDs described here exhibited obvious superiority mainly including satisfactory stability, non-toxicity and photobleaching resistance, and also the whole synthesis procedures for both p-CDs and s-CDs were environmental-friendly. Significantly, p-CDs showed specific binding with pathogenic fungus of Cryptococcus neoformans, and thereby revealing the potential of staining the fungus. Additionally, we employed Cryptococcus neoformans to infect mice, and utilized p-CDs to trace the positions of the fungus, proving the fluorescent-staining prospect of p-CDs.Graphical abstractHerein, we have developed two kinds of carbon dots (CDs) originated from pea (p-CDs) and sesame (s-CDs) through a facile hydrothermal way. Importantly, p-CDs showed the specific binding with the pathogenic fungus of Cryptococcus neoformans, thus exhibited the potential of staining the fungus. In addition, we employed Cryptococcus neoformans to infect the mice, and utilized p-CDs to trace the position of the fungus, proving the fluorescent staining ability of p-CDs.Image 1
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
Home (Search)
Subjects A-Z
Publishers A-Z
Your IP address:
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-