First report of the characterization of a snake venom apyrase (Ruviapyrase) from Indian Russell's viper (Daboia russelii) venom

Int J Biol Macromol. 2018 May;111:639-648. doi: 10.1016/j.ijbiomac.2018.01.038. Epub 2018 Jan 8.

Abstract

A novel apyrase from Russell's viper venom (RVV) was purified and characterized, and it was named Ruviapyrase (Russell's viper apyrase). It is a high molecular weight (79.4 kDa) monomeric glycoprotein that contains 2.4% neutral sugars and 58.4% N-linked oligosaccharides and strongly binds to Concanavalin A. The LC-MS/MS analysis did not identify any protein in NCBI protein database, nevertheless some de novo sequences of Ruviapyrase showed putative conserved domain of apyrase superfamily. Ruviapyrase hydrolysed adenosine triphosphate (ATP) to a significantly greater extent (p < .05) as compared to adenosine diphosphate (ADP); however, it was devoid of 5'-nucleotidase and phosphodiesterase activities. The Km and Vmax values for Ruviapyrase towards ATP were 2.54 μM and 615 μM of Pi released min-1, respectively with a turnover number (Kcat) of 24,600 min-1. Spectrofluorometric analysis demonstrated interaction of Ruviapyrase with ATP and ADP at Kd values of 0.92 nM and 1.25 nM, respectively. Ruviapyrase did not show cytotoxicity against breast cancer (MCF-7) cells and haemolytic activity, it exhibited marginal anticoagulant and strong antiplatelet activity, and dose-dependently reversed the ADP-induced platelet aggregation. The catalytic activity and platelet deaggregation property of Ruviapyrase was significantly inhibited by EDTA, DTT and IAA, and neutralized by commercial monovalent and polyvalent antivenom.

Keywords: Antiplatelet activity; Apyrase; Glycosylation; Russell's viper.

MeSH terms

  • Animals
  • Anticoagulants
  • Antivenins / chemistry*
  • Antivenins / pharmacology
  • Apyrase / chemistry*
  • Apyrase / isolation & purification
  • Apyrase / pharmacology
  • Blood Platelets / drug effects
  • Humans
  • Platelet Aggregation / drug effects
  • Russell's Viper*
  • Viper Venoms / enzymology*

Substances

  • Anticoagulants
  • Antivenins
  • Viper Venoms
  • Apyrase