Interrogating the higher order structures of snake venom proteins

ABSTRACT: Snake venoms contain complex mixtures of proteins that play vital roles in the survival of venomous snakes. In line with their diverse pharmacological activities, the protein compositions of snake venoms can be highly variable, and efforts to characterise the primary structures of such proteins are extensive and ongoing. In addition, a significant knowledge gap exists in terms of higher-order interactionsbetweenproteinsproposedto modulate venom potency, which poses a challenge for treatment of envenomation and development of successful therapeutic applications.Here we use a multifaceted mass spectrometrybased approach to characteriseproteinsfrom the medically significant venomsof Collett’s snake Pseudechis collettiand the puff adder Bitis arietans.Following chromatographic fractionation and bottom-up proteomics identification, native mass spectrometry identified, among other components, a 117 kDa non-covalent L-amino acid oxidase dimer in the P. collettivenom and a 60 kDa C-type lectin tetramer in the B. arietansvenom. Furthermore, a 27.7 kDa covalently-linked phospholipase A2(PLA2) dimer was identified in P. collettivenom, and thePLA2species were shownto adopt a highly compact geometry based on ion mobility measurements. Exploration of the catalytic efficiencies of the monomeric and dimeric forms of PLA2revealed that the dimeric PLA2 possessed greater bioactivity than the monomeric PLA2s.This work contributes to ongoing efforts to catalogue the protein components of snake venoms, and notably,itemphasises the importance of understanding higher-order protein interactions in venomsand the utility of a combined mass spectrometric approachfor this task.

INSTRUMENT(S): LTQ Orbitrap, Synapt MS

ORGANISM(S): Vertebrata <metazoa>

TISSUE(S): Venom

SUBMITTER: Parul Mittal  

LAB HEAD: Tara L. Pukala

PROVIDER: PXD016503 | Pride | 2020-02-17

REPOSITORIES: Pride