@article {8899, title = {Contryphan Genes and Mature Peptides in the Venom of Nine Cone Snail Species by Transcriptomic and Mass Spectrometric Analysis [Next Gen Genomics Facility]}, journal = {J Proteome Res}, volume = {16}, year = {2017}, month = {2017 Feb 03}, pages = {763-772}, abstract = {

The occurrence of contryphans, a class of single-disulfide-bond-containing peptides, is demonstrated by the analysis of the venom of nine species of cone snails. Ten full gene sequences and two partial gene sequences coding for contryphan precursor proteins have been identified by next-generation sequencing and compared with available sequences. The occurrence of mature peptides in isolated venom has been demonstrated by LC-ESI-MS/MS analysis. De novo sequencing of reduced, alkylated contryphans from C. frigidus and C. araneosus provides evidence of sequence variation and post-translational modification, notably gamma carboxylation of glutamic acid. The characterization of Fr965 (C. frigidus) provides a rare example of a sequence lacking Pro at position 5 in the disulfide loop. The widespread occurrence of contryphan genes and mature peptides in the venom of diverse cone snails is suggestive of their potential biological significance.

}, keywords = {Amino Acid Sequence, Animals, Conotoxins, Conus Snail, Mass Spectrometry, Peptides, Peptides, Cyclic, Protein Processing, Post-Translational, Transcriptome, Venoms}, issn = {1535-3907}, doi = {10.1021/acs.jproteome.6b00776}, author = {Vijayasarathy, Marimuthu and Basheer, Soorej M and Franklin, Jayaseelan Benjamin and Balaram, Padmanabhan} } @article {540, title = {A method for comparative metabolomics in urine using high resolution mass spectrometry.}, journal = {J Chromatogr A}, volume = {1443}, year = {2016}, month = {2016 Apr 22}, pages = {83-92}, abstract = {

Developing a workflow for metabolite profiling from biological fluids using mass spectrometry is imperative to extract accurate information. In this study, urine samples from smokers (n=10) and nonsmokers (n=10) were analyzed using an ultrahigh performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) system. For the analysis, two different chromatographic methods [Reversed phase chromatography (RPC) and Hydrophilic interaction liquid chromatography (HILIC)], in two ionization modes (positive and negative) were used. Spiked reserpine (positive ion mode) or taurocholate (negative ion mode) were used for data extraction and normalization. Quality controls (QCs), prepared by pooling urine samples from both smokers and non-smokers (each n=10), were used to assess the reproducibility of the method. The final data output from SIEVE 2.2 after applying a cut-off for QC coefficient of variation (CV) \<20\% and p-value \<0.05 showed 165, 83, 177 and 100 unique components in RP positive/negative, HILIC positive/negative modes, respectively. Statistical analysis showed clustering of the two groups and the QCs, while the variable importance in projection (VIP) scores for the top fifteen metabolites in each of the four modes indicated the metabolites most responsible for the differences. Application of the developed workflow for comparative metabolomic analysis of urine in different diseased models will be of great use in the field of clinical metabolomics.

}, keywords = {Chromatography, Liquid, Chromatography, Reverse-Phase, Hydrophobic and Hydrophilic Interactions, Mass Spectrometry, Metabolomics, Reproducibility of Results, Urinalysis}, issn = {1873-3778}, doi = {10.1016/j.chroma.2016.02.080}, author = {Ramakrishnan, Padma and Nair, Sreenath and Rangiah, Kannan} } @article {497, title = {Protective effect of Euphorbia hirta and its components against snake venom induced lethality. [Mass spectrometry - Metabolomics]}, journal = {J Ethnopharmacol}, volume = {165}, year = {2015}, month = {2015 May 13}, pages = {180-90}, abstract = {

ETHNOPHARMACOLOGICAL RELEVANCE: Despite the use of snake anti-venom therapy, herbal medicine is still in practice to treat snakebites. Euphorbia hirta is traditionally used as antidote for snakebites and also for numerous other ailments. However, the scientific evidence for its anti-snake venom property is still lacking.

MATERIALS AND METHODS: Methanolic extract of E. hirta was evaluated for anti-venom activity under in vitro and ex vivo conditions. Histopathological changes in the vital organs of the mice were also monitored. UHPLC-SRM/MS was used to estimate the phenolic constituents whereas GC-MS analysis was performed to analyze the volatile metabolites present. The major compound was further evaluated for its contribution to the overall inhibitory potential of the extract.

RESULTS: Methanolic extract of E. hirta completely inhibited the venom enzymes under in vitro and reduced the edema ratio. The extract increased the survival time (\>24h) of mice which was further evidenced by histopathological analysis of vital organs. Phytochemical analysis revealed higher content of phenolic (144 mg/g extract) compounds in the extract. UHPLC-SRM/MS demonstrated that ellagic acid, gallic acid and quinic acid are the major phenolics whereas GC-MS analysis revealed pyrogallol as the major constituent (60.07\%) among the volatile components of the extract. It was also shown that pyrogallol has the ability to differentially inhibit venom protease but not phospholipase A2.

CONCLUSION: The present study confirmed that E. hirta methanolic extract was able to completely inhibit Naja naja venom induced toxicity under in vitro as well as ex vivo conditions, thus providing scientific evidence to its traditional use.

}, keywords = {Animals, Chromatography, High Pressure Liquid, Cobra Venoms, Euphorbia, Male, Mass Spectrometry, Mice, Phytotherapy, Plant Extracts, Snake Bites, Snake Venoms}, issn = {1872-7573}, doi = {10.1016/j.jep.2015.02.044}, author = {Gopi, Kadiyala and Renu, Kadali and Sannanaik Vishwanath, Bannikuppe and Jayaraman, Gurunathan} } @article {533, title = {A rapid, nonradioactive assay for measuring heparan sulfate C-5 epimerase activity using hydrogen/deuterium exchange-mass spectrometry.}, journal = {Methods Mol Biol}, volume = {1229}, year = {2015}, month = {2015}, pages = {209-19}, abstract = {

Heparin and heparan sulfate (HS) glycosaminoglycans have important roles in anticoagulation, human development, and human diseases. HS C5-epimerase, which catalyzes the epimerization of GlcA to IdoA, is a crucial enzyme involved in the biosynthesis of heparin-related biomolecules. Here, we describe a detailed method for measuring the total activity of HS C5-epimerase that involves the following steps: H/D exchange upon epimerization of the substrate with HS C5-epimerase, low-pH nitrous acid treatment of the substrate, the separation of low-pH nitrous acid-cleaved disaccharides using HPLC, and mass spectrometry analysis. This nonradioactive method is rapid and sensitive and, importantly, allows us to study the reversible nature of HS C5-epimerase.

}, keywords = {Animals, Biocatalysis, Carbohydrate Epimerases, Chromatography, Ion Exchange, Chromatography, Liquid, Deuterium Exchange Measurement, Disaccharides, Enzyme Assays, Glucuronic Acid, Heparitin Sulfate, Humans, Iduronic Acid, Mass Spectrometry, Sf9 Cells}, issn = {1940-6029}, doi = {10.1007/978-1-4939-1714-3_19}, author = {Babu, Ponnusamy and Victor, Xylophone V and Raman, Karthik and Kuberan, Balagurunathan} } @article {537, title = {Redox proteomics of thiol proteins in mouse heart during ischemia/reperfusion using ICAT reagents and mass spectrometry.}, journal = {Free Radic Biol Med}, volume = {58}, year = {2013}, month = {2013 May}, pages = {109-17}, abstract = {

There is strong evidence for the involvement of reactive oxygen species in ischemia/reperfusion injury. Although oxidation of individual thiol proteins has been reported, more extensive redox proteomics of hearts subjected to ischemia/reperfusion has not been performed. We have carried out an exploratory study using mass spectrometry with isotope-coded affinity tags (ICAT) aimed at identifying reversible oxidative changes to protein thiols in Langendorff perfused isolated mouse hearts subjected to 20 min ischemia with or without aerobic reperfusion for 5 or 30 min. Reduced thiols were blocked by adding N-ethylmaleimide during protein extraction, then reversibly oxidized thiols in extracts of control perfused and treated hearts were reduced and labeled with the light and heavy ICAT reagents, respectively. Protein extracts were mixed in equal amounts and relative proportions of the isotope-labeled peaks were used to quantify oxidative changes between the control and the treated groups. Approximately 300 peptides with ICAT signatures were reliably identified in each sample, with 181 peptides from 118 proteins common to all treatments. A proportion showed elevated ICAT ratios, consistent with reversible thiol oxidation. This was most evident after early reperfusion, with apparent reversal after longer reperfusion. In comparison, there was gradual accumulation of protein carbonyls and loss of GSH with longer reperfusion. Many of the thiol changes were in mitochondrial proteins, including components of electron transport complexes and enzymes involved in lipid metabolism. The results are consistent with mitochondria being a major site of oxidant generation during early cardiac reperfusion and mitochondrial thiol proteins being targets for oxidation.

}, keywords = {Animals, Isotope Labeling, Mass Spectrometry, Mice, Mitochondrial Proteins, Myocardium, Oxidation-Reduction, Proteomics, Reactive Oxygen Species, Reperfusion Injury, Sulfhydryl Compounds}, issn = {1873-4596}, doi = {10.1016/j.freeradbiomed.2013.01.021}, author = {Kumar, Vikas and Kleffmann, Torsten and Hampton, Mark B and Cannell, Mark B and Winterbourn, Christine C} } @article {519, title = {Unexpected histone H3 tail-clipping activity of glutamate dehydrogenase. (Mass spectrometry - Proteomics)}, journal = {J Biol Chem}, volume = {288}, year = {2013}, month = {2013 Jun 28}, pages = {18743-57}, abstract = {

Clipping of histone tails has been reported in several organisms. However, the significance and regulation of histone tail clipping largely remains unclear. According to recent discoveries H3 clipping has been found to be involved in regulation of gene expression and chromatin dynamics. Earlier we had provided evidence of tissue-specific proteolytic processing of histone H3 in White Leghorn chicken liver nuclei. In this study we identify a novel activity of glutamate dehydrogenase (GDH) as a histone H3-specific protease in chicken liver tissue. This protease activity is regulated by divalent ions and thiol-disulfide conversion in vitro. GDH specifically clips H3 in its free as well as chromatin-bound form. Furthermore, we have found an inhibitor that inhibits the H3-clipping activity of GDH. Like previously reported proteases, GDH too may have the potential to regulate/modulate post-translational modifications of histone H3 by removing the N-terminal residues of the histone. In short, our findings identify an unexpected proteolytic activity of GDH specific to histone H3 that is regulated by redox state, ionic concentrations, and a cellular inhibitor in vitro.

}, keywords = {Amino Acid Sequence, Animals, Binding Sites, Brain, Chickens, Chromatin, Cysteine Proteases, Disulfides, Epigenesis, Genetic, Gene Expression Regulation, Enzymologic, Glutamate Dehydrogenase, Histones, Hydrogen-Ion Concentration, Liver, Mass Spectrometry, Mice, Molecular Sequence Data, Rats, Recombinant Proteins, Salts, Sulfhydryl Compounds, Temperature}, issn = {1083-351X}, doi = {10.1074/jbc.M113.462531}, author = {Mandal, Papita and Verma, Naveen and Chauhan, Sakshi and Tomar, Raghuvir S} }