Mass Spectrometry Based Proteomics Investigation of Five South Asian Snake Venoms to Unravel the Venom Complexity

Description:
Snake venoms are mixtures of different protein families, and these families contain many different toxins or toxin isoforms. Snake venoms have various actions on cells and tissues such as digestion of cells, disruption of blood procoagulants and anticoagulants, production of oxidizing agents, breakdown of collagen, and the disruption of nerve tissues. There is a large degree of variability in venom composition at all taxonomic levels. This study presents a proteomics analysis of five snake venoms of the species Indian Cobra (NN) (Naja naja), Russell’s Viper (RV) (Daboia russelii), Indian Krait (BC) (Bungarus caeruleus), Hump-nosed Viper (HPN) (Hypnale hypnale), Green Pit Viper (GPV) (Trimeresurus trigonocephalus). Venom proteins were separated using SDS-PAGE. In-gel trypsin/LysC digestion was performed and tryptic peptides were lyophilized before LC-MS/MS analysis. The LC-MS/MS analysis was performed on a fully automated proteomic technology platform that includes a Dionex UltiMate ® 3000 HPLC system connected to a Q Exactive HF-X mass spectrometer. The peptide spectrum matching of MS/MS spectra of each file was searched against the NCBI Serpentes (TaxID:8570) and Toxicofera (TaxID: 1329911) database using the Sequest algorithm within Proteome Discoverer. The Sequest database search was performed with the following parameters: trypsin enzyme cleavage specificity, 2 possible missed cleavages, 10 ppm mass tolerance for precursor ions, 0.02 Da mass tolerance for fragment ions. Search parameters permitted dynamic modification of methionine oxidation (+15.9949 Da) and static modification of carbamidomethylation (+57.0215 Da) on cysteine. Peptide assignments from the database search were filtered down to a 1% FDR. For each venom sample unique peptides and unique proteins were identified respectively as follows NN (485, 135), RV (424,134), BC (176, 65), HPN (129,79) and GPV (258,103). The detailed experimental conditions and results will be presented at the conference.