title: Purification and characterization of a phospholipase A2 isoenzyme isolated from Lachesis muta snake venom.
abstract: A new phospholipase A2 (PLA2) isoenzyme was isolated from Lachesis muta crude venom, and was named LM-PLA2-II. This enzyme was purified by gel filtration on a Sephacryl S-200 HR column followed by reverse-phase chromatography on a C2/C18 column. LM-PLA2-II consists of a single polypeptide chain with an apparent molecular mass of 18 kDa and an isoelectric point at pH 5.4. The amino terminal sequence of the enzyme revealed a high degree of homology with other PLA2s from several sources. LM-PLA2-II has a high indirect hemolytic activity and a potent inhibitory effect on platelet aggregation induced by ADP and collagen. It also produces a significant paw edema reaction in rats. The edematous response in rats was abolished by pretreatment with either indomethacin or dexamethasone, suggesting the involvement of cyclo-oxygenase. Pretreatment of LM-PLA2-II with p-bromophenacyl bromide abolished all of these actions, clearly indicating that the biological activities, including the edematogenic effect, are dependent entirely on its enzymatic activity.
authors: Departamento de Bioquímica Médica, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, RJ, Rio de Janeiro, Brazil.
authors: André L
authors: AL
authors: Fuly
authors: Ana Luisa P
authors: AL
authors: de Miranda
authors: Russolina B
authors: RB
authors: Zingali
authors: Jorge A
authors: JA
authors: Guimarães
mesh_terms: D000244:Adenosine Diphosphate / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology; D003094:Collagen / Q000502:physiology; D004487:Edema / Q000139:chemically induced; D006461:Hemolysis / Q000187:drug effects; D006470:Hemorrhage / Q000139:chemically induced; D007527:Isoenzymes / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D054467:Phospholipases A2; D010975:Platelet Aggregation Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D014757:Viper Venoms / Q000201:enzymology*; D017819:Viperidae / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D010975:Platelet Aggregation Inhibitors; D014757:Viper Venoms; D000244:Adenosine Diphosphate; D003094:Collagen; D010741:Phospholipases A; D054467:Phospholipases A2