title: Role of catalytic function in the antiplatelet activity of phospholipase A2 cobra (Naja naja naja) venom.
abstract: Three acidic phospholipases A2 from Indian cobra (Naja naja naja) venom inhibited platelet aggregation in platelet rich plasma induced separately by ADP, collagen and epinephrine with different potencies. The order of inhibition was epinephrine > collagen > ADP. They did not inhibit platelet aggregation induced by arachidonic acid (10 microM). The inhibition was dependent on concentration of the protein and the time of incubation of the phospholipases A2 with platelet rich plasma. Parabromophenacyl bromide modified PLA2 enzymes lost their enzymatic activity as well as platelet aggregation inhibition activity suggesting the involvement of catalytic function in platelet aggregation inhibitory activity.
authors.affiliation: Department of Studies in Biochemistry, University of Mysore, Manasagangotri, India.
authors.forename: L M
authors.initials: LM
authors.lastname: Rudrammaji
authors.forename: K D
authors.initials: KD
authors.lastname: Machiah
authors.forename: T P
authors.initials: TP
authors.lastname: Kantha
authors.forename: T V
authors.initials: TV
authors.lastname: Gowda
mesh_terms: D000098:Acetophenones / Q000494:pharmacology*; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000322:Adrenergic Agonists / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002384:Catalysis; D003094:Collagen / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004546:Elapid Venoms / Q000737:chemistry / Q000201:enzymology* / Q000302:isolation & purification; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism; D010741:Phospholipases A / Q000302:isolation & purification / Q000378:metabolism*; D054467:Phospholipases A2; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000098:Acetophenones; D000322:Adrenergic Agonists; D004546:Elapid Venoms; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D010975:Platelet Aggregation Inhibitors; D000244:Adenosine Diphosphate; D003094:Collagen; D010741:Phospholipases A; D054467:Phospholipases A2; C006821:4-bromophenacyl bromide; D004837:Epinephrine