title: Characterization of a Kunitz-type protease inhibitor peptide (Rusvikunin) purified from Daboia russelii russelii venom.
abstract: The snake venom may be considered as a potent source of untapped therapeutic proteins and peptides. The peptide mass fingerprinting and N-terminal sequence alignment of a 6.9kDa peptide named Rusvikunin from Daboia russelii russelii venom show the presence of putative conserved domains of the KU superfamily. Further, BLAST analysis of two of the de novo peptide sequences of Rusvikunin demonstrates significant sequence homology with serine proteases reported in the NCBI database. Rusvikunin possesses conserved cysteine residues and Arg15 at the P1 position. It inhibits amidolytic activity of trypsin (IC50=50nmol/l), plasmin (IC50=1.1μmol/l), and fibrinogen clotting as well as plasma clotting activity of thrombin (IC50=1.3μmol/l); however, it does not inhibit the amidolytic activity of chymotrypsin, thrombin, factor Xa, and tissue plasminogen activator. Rusvikunin is a glycoprotein, demonstrates dose-dependent BAEE-esterase activity. It does not show lethality in mice or in vitro cytotoxicity against mammalian cells but shows in vivo anticoagulant activity 6h after i.p. injection in the mouse model. The commercial polyvalent and monovalent antivenom failed to inhibit the functional properties of Rusvikunin. The possible biomedical applications of Rusvikunin in the treatment and/or prevention of cardiovascular disorders such as thrombosis and trypsin-induced inflammation are suggested.
authors.affiliation: School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639-0017, USA; Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784 028, Assam, India. Electronic address: akm@tezu.ernet.in.
authors.forename: Ashis K
authors.initials: AK
authors.lastname: Mukherjee
authors.affiliation: School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639-0017, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Mackessy
authors.affiliation: Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784 028, Assam, India.
authors.forename: Sumita
authors.initials: S
authors.lastname: Dutta
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy; D008297:Male; D051379:Mice; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D013927:Thrombosis / Q000139:chemically induced / Q000188:drug therapy; D014357:Trypsin / Q000633:toxicity; D014757:Viper Venoms / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D002352:Carrier Proteins; C573935:DrKIn-I protein, Daboia russelii; D010455:Peptides; D014757:Viper Venoms; C000594156:rusvikunin peptide, Daboia russelii russelii; D014357:Trypsin
keywords: Anti-plasmin; Anticoagulant; BPTI; Russell's Viper; Thrombin inhibitor; Trypsin inhibitor