Several studies have shown that Asp-49 is the residue that controls calcium binding in, and so plays a critical role in the calcium-mediated activation of, low-M(r) group I-III phospholipases A2 (PLA2s). The present paper provides experimental evidence that Asp-49 is not an absolute prerequisite for the enzymic activity of PLA2s, and that proteins with amino acid(s) other than Asp at position 4...

Echicetin, a new protein isolated from Echis carinatus venom by reverse phase and ion exchange chromatography specifically inhibited agglutination of fixed platelets induced by several platelet glycoprotein Ib (GPIb) agonists, such as bovine von Willebrand factor (vWF), alboaggregins, and human vWF in the presence of botrocetin. Unlike alboaggregins, echicetin bound to GPIb but did not induce a...

Recombinant human prothrombin (r-prothrombin) and recombinant mutant prothrombin with active site Asp419 substituted by Asn (D419N-prothrombin) were expressed in recombinant CHO cells, isolated and purified from the fermentation supernatant. The r-Prothrombin and D419N-prothrombin were digested by both Echis carinatus venom and Oxyuranus scutellatus venom. Prior to, during and after activation,...

The purification, complete amino acid sequence, and biological activity are described for several homologous snake venom proteins that are platelet glycoprotein (GP) IIb-IIIa antagonists and potent inhibitors of platelet aggregation. The primary structures of kistrin (from Agkistrodon rhodostoma), bitan (from Bitis arietans), three isoforms of trigramin (from Trimeresusus gramineus), and an iso...

H EMORRHAGE is the outstanding phenomenon observed following the bite by snakes of the Viperidae and Crotalidae families. Subjects bitten by these snakes show local hemorrhage near the site of the bite, slowly extending proximally, and, after death, widespread hemorrhage in many internal organs. In the explanation of the hemorrhage, two mechanisms have been invoked; damage to the vessel wall ca...

background: information on the epidemiology of venomous snake species responsible for envenomation to humans in iran has not been well documented. in the kashan city, venomous snakebite remains a recurring medical problem. information providing the correct identification of snake species responsible for envenomation in this geographic region would be useful to regional medicalclinics and person...