title: Enzymatic characterization of a novel phospholipase A2 from Crotalus durissus cascavella rattlesnake (Maracambóia) venom.
abstract: The PLA2 and crotapotin subunits of crotoxin from Crotalus durissus cascavella venom were purified by a combination of high-performance liquid chromatography (HPLC) molecular exclusion (Protein Pack 300SW column) and reverse-phase HPLC (RP-HPLC). Tricine SDS-PAGE showed that the PLA2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kDa, respectively. The amino acid composition of the PLA2 showed the presence of 14 half-cysteines and a high content of basic residues (Lys, Arg, His), whereas the crotapotins were rich in hydrophobic, negatively charged residues and half-cysteines. The PLA2 showed allosteric behavior, with maximal activity at pH 8.3 and 35-40 degrees C. C. d. cascavella PLA2 required Ca2+ for activity but was inhibited by Cu2+ and Zn2+ and by Cu2+ and Mg2+ in the presence and absence of Ca2+, respectively. Crotapotin (F3) and heparin inhibited the catalytic activity of the PLA2 by acting as allosteric inhibitors.
authors: Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas  SP, Brazil.
authors: D G
authors: DG
authors: Beghini
authors: M H
authors: MH
authors: Toyama
authors: S
authors: S
authors: Hyslop
authors: L C
authors: LC
authors: Sodek
authors: Novello
authors: S
authors: S
authors: Marangoni
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003435:Crotalid Venoms / Q000201:enzymology*; D017839:Crotalus; D003439:Crotoxin / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D010741:Phospholipases A / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D054467:Phospholipases A2
chemical_list: D000596:Amino Acids; D003435:Crotalid Venoms; D004791:Enzyme Inhibitors; D003439:Crotoxin; D010741:Phospholipases A; D054467:Phospholipases A2