Purification and characterization of a platelet aggregation inhibitor and anticoagulant Cc 5_NTase, CD 73‐like, from Cerastes cerastes venom

The present study is the first attempt to report the characterization of a nucleotidase from Cerastes cerastes venom. A 70 kDa 5′‐nucleotidase (Cc‐5′NTase) was purified to homogeneity. The amino acid sequence of Cc‐5′NTase displayed high homology with many nucleotidases. Its activity was optimal at pH 7 with a specific hydrolytic activity toward mono‐, di‐, and triphosphate adenylated nucleotides. Cc‐5′NTase preferentially hydrolyzed ADP and obeyed Michaelis–Menten kinetics. Among the metals and inhibitors tested, Ni2+ and Mg2+ completely potentiated enzyme activity, whereas EGTA, PMSF, iodoacetamide, vanillic acid, vanillyl mandelic acid, and 1,10‐phenanthroline partially abolished its activity. Cc‐5′NTase was not lethal for mice at 5 mg/kg and exhibited in vivo anticoagulant effect. It also dose‐dependently inhibited adenosine diphosphate‐induced platelet aggregation by converting adenosine diphosphate to adenosine and prohibited arachidonic acid‐induced aggregation but was not effective on fibrinogen‐induced aggregation. Cc‐5′NTase could be a good tool as pharmacological molecule in thrombosis diagnostic and/or therapy.