title: Dissociation of enzymatic activity from toxic properties of the most basic phospholipase A2 from Vipera russelli snake venom by guanidination of lysine residues.
abstract: The most basic phospholipase A2 VRV-PL-VIIIa purified from Russell's viper venom is a toxic enzyme. It induced neurotoxicity, myotoxicity, and oedema and was lethal to mice at 5.3 micrograms/g body weight. It also inhibited the coagulation of the human plasma. The epsilon-amino groups of lysine residues of the toxic enzyme VRV-PL-VIIIa were guanidinated with o-methylisourea. Guanidination of the enzyme did not alter the enzymatic activity markedly. The guanidinated enzyme became non-lethal in doses up to 16 micrograms/g body weight, and failed to elicit neurotoxic symptoms in experimental animals and oedema in the foot pads of mice. Also, its myotoxic and anticoagulant potencies were decreased significantly.
authors.affiliation: Department of Studies in Biochemistry, University of Mysore, India.
authors.forename: A S
authors.initials: AS
authors.lastname: Babu
authors.forename: T V
authors.initials: TV
authors.lastname: Gowda
mesh_terms: D000818:Animals; D019791:Guanidine; D006146:Guanidines / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D051379:Mice; D010741:Phospholipases A / Q000737:chemistry* / Q000633:toxicity*; D054467:Phospholipases A2; D017840:Daboia; D013329:Structure-Activity Relationship; D014757:Viper Venoms / Q000201:enzymology* / Q000633:toxicity*
chemical_list: D006146:Guanidines; D014757:Viper Venoms; D010741:Phospholipases A; D054467:Phospholipases A2; D019791:Guanidine; D008239:Lysine