NPP-BJ, a nucleotide pyrophosphatase/phosphodiesterase from Bothrops jararaca snake venom, inhibits platelet aggregation

Abstract

Enzymes of the pyrophosphatase/phosphodiesterase family have multiple roles in extracellular nucleotide metabolism and in the regulation of nucleotide-based intercellular signaling. Snake venoms contain enzymes that hydrolyze nucleic acids and nucleotides, but their function is poorly understood. Here we describe for the first time the isolation and functional characterization of a soluble phosphodiesterase from Bothrops jararaca venom, which shows amino acid sequence similarity to mammalian nucleotide pyrophosphatase/phosphodiesterase 3 (NPP3), and inhibits ADP-induced platelet aggregation. The enzyme, named NPP-BJ, showed an apparent molecular mass of 228 kDa by size exclusion chromatography. NPP-BJ exhibited nuclease activity as well as pyrophosphatase and phosphatase activities, preferentially hydrolyzing nucleoside 5'-triphosphates over nucleoside 5'-diphosphates, but was not active upon nucleoside 5'-monophosphates. Depending on the substrate used, dithiothreitol and EDTA differently inhibited the catalytic activity of NPP-BJ. Platelet aggregation induced by ADP was also abrogated by NPP-BJ, whereas thrombin-induced platelet aggregation was only slightly attenuated. However, polyclonal antibodies raised against NPP-BJ could not abolish the lethal activity of B. jararaca venom. Altogether, these results show that NPP-BJ has a minor contribution to the lethal activity of this venom, but interferes with mechanisms of ADP-induced platelet aggregation.

Phosphodiesterase from Vipera lebetina venom – Structure and characterization

“…Followed by discovery of restrictases the importance of SVPDE diminished remarkably. Later several papers regarding structural features of SVPDE have been published [17,19,35,36]. The PDE from the venom of Bothrops alternatus showed a single band on SDS-PAGE with molecular mass of 105 kDa in both reduced and nonreduced conditions; so this enzyme is a single chain polypeptide [36].…”

“…The biological properties of VLPDE and other snake venom PDEs are slightly different. For example, PDEs from Bothrops jararaca [17] and T. stejnegeri [19] cleave ATP more effectively than ADP, in contrast to VLPDE. The inhibition of platelet aggregation has so far been shown (in addition to VLPDE) only with T. stejnegeri enzyme [19] where the effect on platelets is drastic.…”

A proteomic analysis of Pakistan Daboia russelii russelii venom and assessment of potency of Indian polyvalent and monovalent antivenom

“…PDE sequentially hydrolyses phosphodiester bond from the 3′ terminus of polynucleotides and affects blood coagulation and modulation of platelet function in victims [62,63]. In Pakistan RVV we have identified 2 PDE enzymes ( Table 3, Supplementary Table S1, Supplementary Fig.…”

Phosphodiesterase from Daboia russelli russelli venom: Purification, partial characterization and inhibition of platelet aggregation

“…Phosphodiesterase and phosphatase activities of crude venom and purified enzyme were measured using bispNPP and pNPP as substrates respectively (Santoro et al, 2009). TMP-pNPP is a better substrate than bis-pNPP.…”

“…In literature, this enzyme is referred as an exonuclease since it also catalyses the hydrolysis of DNA and RNA in a progressive fashion beginning at the 3 0 -end of the polynucleotide liberating 5 0 -mononucleotides. For this reason, they are used in the elucidation of structure and sequence of DNAs (Ho and Gilham, 1973;Santoro et al, 2009). PDEs are ubiquitously distributed in snake venoms (Dhananjaya and D'Souza, 2010).…”