title: Biochemical and pharmacological characterization of three toxic phospholipase A2s from Daboia russelii snake venom.
abstract: Three isoenzymes of phospholipase A2 (PLA2), VRV-PL-IIIc, VRV-PL-VII, and VRV-PL-IX were isolated from Daboia russelii snake venom. The venom, upon gel filtration on Sephadex G-75 column, resolved into six peaks (DRG75 I-VI). The VRV-PL-IIIc was purified by subjecting DRG75II to homogeneity by rechromatography in the presence of 8M urea on Sephadex G-75 column. The other two isoenzymes VRV-PL-VII and VRV-PL-IX were purified by subjecting DRG75III to ion exchange chromatography on CM-Sephadex C-25 column. Mol wt. for the three PLA2s, VRV-PL-IIIc, VRV-PL-VII, and VRV-PL-IX are 13.003kDa, 13.100kDa and 12.531kDa respectively. The VRV-PL-IIIc is not lethal to mice up to 14mg/kg body weight but it affects blood sinusoids and causes necrosis of the hepatocytes in liver. It causes hemorrhage in kidney and shrinkage of renal corpuscles and renal tubules. The LD50s for VRV-PL-VII and VRV-PL-IX are 7 and 7.5mg/kg body weight respectively. They induced neurotoxic symptoms similar to VRV-PL-V. All the three PLA2s are anticoagulant and induced varying degree of edema in the foot pads of mice. VRV-PL-V and VRV-PL-VII are shown to act as pre and post synaptic toxins, while VRV-PL-IX acts as presynaptic toxin. This is evident from experiments conducted on cultured hippocampal neurons by patch clamp electrophysiology.
authors.affiliation: Department of studies in Biochemistry University of Mysore, Manasagangothri, Mysore 570006, India; Post Graduate Department of Biochemistry, JSS College, Ooty Road, Mysore 570025, India. Electronic address: kumarjr2013@gmail.com.
authors.forename: J R
authors.initials: JR
authors.lastname: Kumar
authors.affiliation: Division of Analytical Psychopharmacology, New York State Psychiatric Institute, USA; Department of Psychiatry, Orangeburg, NY 10962, USA; Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
authors.forename: Balapal S
authors.initials: BS
authors.lastname: Basavarajappa
authors.affiliation: Department of studies in Biochemistry University of Mysore, Manasagangothri, Mysore 570006, India.
authors.forename: B S
authors.initials: BS
authors.lastname: Vishwanath
authors.affiliation: Department of studies in Biochemistry University of Mysore, Manasagangothri, Mysore 570006, India.
authors.forename: T Veerabasappa
authors.initials: TV
authors.lastname: Gowda
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology; D004487:Edema / Q000139:chemically induced; D006470:Hemorrhage / Q000139:chemically induced; D022781:Hepatocytes / Q000187:drug effects; D007527:Isoenzymes / Q000737:chemistry / Q000494:pharmacology; D007684:Kidney Tubules / Q000187:drug effects; D008099:Liver / Q000187:drug effects; D008297:Male; D051379:Mice; D009336:Necrosis / Q000139:chemically induced; D054467:Phospholipases A2 / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology*; D012910:Snake Venoms / Q000737:chemistry*; D014757:Viper Venoms / Q000737:chemistry*
chemical_list: D000925:Anticoagulants; D007527:Isoenzymes; D012910:Snake Venoms; D014757:Viper Venoms; D054467:Phospholipases A2
keywords: Daboia russelii venom; Pre/post synaptic neurotoxin; Venom PLA2