Interrogating the Venom of the Viperid Snake Sistrurus catenatus edwardsii by a Combined Approach of Electrospray and MALDI Mass Spectrometry.

Alex Chapeaurouge,André Teixeira-Ferreira,Richard H Valente,Paulo C Carvalho,R Manjunatha Kini,Qingsong Lin,Md Abu Reza,Jonas Perales,Stephen P Mackessy,Partha Mukhopadhyay

doi:10.1371/journal.pone.0092091

Abstract

The complete sequence characterization of snake venom proteins by mass spectrometry is rather challenging due to the presence of multiple isoforms from different protein families. In the present study, we investigated the tryptic digest of the venom of the viperid snake Sistrurus catenatus edwardsii by a combined approach of liquid chromatography coupled to either electrospray (online) or MALDI (offline) mass spectrometry. These different ionization techniques proved to be complementary allowing the identification a great variety of isoforms of diverse snake venom protein families, as evidenced by the detection of the corresponding unique peptides. For example, ten out of eleven predicted isoforms of serine proteinases of the venom of S. c. edwardsii were distinguished using this approach. Moreover, snake venom protein families not encountered in a previous transcriptome study of the venom gland of this snake were identified. In essence, our results support the notion that complementary ionization techniques of mass spectrometry allow for the detection of even subtle sequence differences of snake venom proteins, which is fundamental for future structure-function relationship and possible drug design studies.

Highlights

Snake venoms represent rich sources of biologically active peptides and proteins and serve as versatile platforms for the discovery and development of drug lead substances [1].PLOS ONE | DOI:10.1371/journal.pone.0092091 May 8, 2015Venom of Sistrurus Analyzed by Mass Spectrometry
Envenomation by viperid snakes frequently manifests as a complex medical syndrome dominated by hemorrhagic and inflammatory processes triggered by the combined enzymatic actions of metalloproteinases, serine proteinases and phospholipases A2 [12,13,14], as well as by the detrimental effects of C-type lectins (CLP) on platelet function [15]
Only a few studies have noted the presence of peptides related to the prodomain of snake venom metalloproteinases (SVMP) in the venom [19, 20] and it might be that in most cases the prodomain of the precursor protein is enzymatically removed before its secretion into the venom gland

Summary

Introduction

Snake venoms represent rich sources of biologically active peptides and proteins and serve as versatile platforms for the discovery and development of drug lead substances [1]. A comparative study of the venom proteomes of four different Sistrurus taxa has revealed an overview of the different protein families of the corresponding venoms, as evidenced by BLAST analysis of the detected sequences [7]. Our analysis revealed the presence of snake venom protein families not detected in the venom gland transcriptome or previous studies, including glutaminyl cyclase, renin-like aspartic protease, and ecto-5'-nucleotidase. These results support the view that an in-depth analysis of the venom proteome is complementary to transcriptomic venom gland studies and will improve our understanding of the interplay of the different venom proteins on the target prey

Materials and Methods

Results and Discussion

Conclusions