title: Purification and activity of two phospholipase enzymes from Naja nigricolis nigricolis Reinhardt venom.
abstract: Two phospholipase enzymes NN1 and NN2 were purified from the venom of Naja nigricolis nigricolis Reinhardt to apparent homogeneity. NN1 was purified by a two-step anion-exchange chromatography on DEAE-cellulose column while NN2 was purified by a combination of anion-exchange chromatography and gel filtration on Sephadex G-150. The enzyme NN1 moved homogenously on acrylamide gel as a monomer with a molecular weight of 65 kDa while NN2 was a dimer of 71 kDa. Both enzymes were clearly separated. Both enzymes hydrolyzed L-alpha-phosphatidyl choline with activities of 345.5 for NN1 and 727.8 micromol min(-1) x mg(-1) for NN2. The dimeric 71-kDa enzyme has a higher haemolytic and anticoagulant activity than the monomeric 65-kDa enzyme. It is apparent that the dimeric enzyme has a more pronounced activity than the monomer has, thus toxic activity may be related to the hydrolysis of phospholipids.
authors.affiliation: Department of Pharmacognosy and Drug Development, Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria, Nigeria.
authors.forename: M S
authors.initials: MS
authors.lastname: Abubakar
authors.forename: A J
authors.initials: AJ
authors.lastname: Nok
authors.forename: E M
authors.initials: EM
authors.lastname: Abdurahman
authors.forename: A K
authors.initials: AK
authors.lastname: Haruna
authors.forename: M
authors.initials: M
authors.lastname: Shok
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange / Q000379:methods; D019281:Dimerization; D004546:Elapid Venoms / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D008970:Molecular Weight; D010741:Phospholipases A / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D000925:Anticoagulants; D004546:Elapid Venoms; D007527:Isoenzymes; D010741:Phospholipases A