title: Elucidation of procoagulant mechanism and pathophysiological significance of a new prothrombin activating metalloprotease purified from Daboia russelii russelii venom.
abstract: The procoagulant proteases present in Russell's Viper venom (RVV) are responsible for promoting consumption coagulopathy in victims. In this study, a procoagulant metalloprotease (Rusviprotease) possessing prothrombin activating and α-fibrinogenase properties has been purified and characterized from RVV. Rusviprotease is a 26.8 kDa glycoprotein which also exists in other multimeric forms. The peptide mass fingerprinting and secondary structure analyses of Rusviprotease revealed its similarity with snake venom prothrombin activators and metalloproteases. Similar to group A prothrombin activators, Rusviprotease cleaved prothrombin independent of any co-factor requirement generating meizothrombin which is further cleaved to form thrombin. The Km and Vmax values of Rusviprotease towards prothrombin were determined to be 1.73 μM, and 153.5 nM thrombin generated/min/μmoles of Rusviprotease, respectively. The Km and Vmax values of Rusviprotease towards fibrinogen were calculated to be 3.14 μM and 78.7 nmol/min, respectively. Spectrofluorometric study provided the evidence of interaction between Rusviprotease and factor Xa with a Kd value of 6.64 nM. This interaction augmented the prothrombin activating property of the factor Xa-prothrombinase-Rusviprotease complex by 2.5 fold. Intravenous injection of Rusviprotease to BALB/c mice (0.1 mg/kg) resulted in in vivo defibrinogenation rendering the blood incoagulable. In conclusion, Rusviprotease is the first example of a prothrombin activator with fibrinogenolytic property purified from Daboia russelii russelii venom.
authors: Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, School of Science, Tezpur University, Tezpur 784 028, Assam, India.
authors: Rupamoni
authors: R
authors: Thakur
authors: Division of Pharmaceutical Technology, Defense Research Laboratory, Tezpur 784 001, Assam, India.
authors: Pronobesh
authors: P
authors: Chattopadhyay
authors: Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati 781 039, Assam, India.
authors: Siddharth S
authors: SS
authors: Ghosh
authors: Microbial Biotechnology and Protein Research Laboratory, Department of Molecular Biology and Biotechnology, School of Science, Tezpur University, Tezpur 784 028, Assam, India. Electronic address: akm@tezu.ernet.in.
authors: Ashis K
authors: AK
authors: Mukherjee
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects; D005591:Chemical Fractionation; D003029:Coagulants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D004912:Erythrocytes / Q000187:drug effects; D006041:Goats / Q000097:blood; D045726:Metalloproteases / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D008807:Mice, Inbred BALB C; D010949:Plasma / Q000187:drug effects; D017840:Daboia; D023382:Toxicity Tests, Acute; D014757:Viper Venoms / Q000737:chemistry* / Q000633:toxicity
chemical_list: D003029:Coagulants; D014757:Viper Venoms; D045726:Metalloproteases
keywords: Metalloprotease; Procoagulant protein; Prothrombin activator; Russell's Viper; Snake venom