title: Purification and characterization of three distinct types of phospholipase A2 inhibitors from the blood plasma of the Chinese mamushi, Agkistrodon blomhoffii siniticus.
abstract: Three distinct types of phospholipase A2 (PLA2) inhibitory proteins (PLIalpha, PLIbeta, and PLIgamma) were isolated from the blood plasma of the Chinese mamushi, Agkistrodon blomhoffii siniticus. PLIalpha is an inhibitor that we have already purified and whose amino acid sequence we have already determined [Ohkura, Inoue, Ikeda and Hayashi (1993) J. Biochem. (Tokyo) 113, 413-419]. It inhibited selectively the group-II acidic PLA2s from Crotalidae venom. PLIbeta was a 160-kDa glycoprotein having a trimeric structure composed of 50-kDa subunits. The amino acid sequence of the first 30 amino acids of the N-terminal part of the 50-kDa subunit was determined and found to have no significant homology to that of known proteins. PLIbeta was a selective inhibitor against the group-II basic PLA2s from Crotalidae venom. Some amino acid residues located in or close to the interfacial binding surface of the group-II basic PLA2s were suggested to be involved in selective binding to PLIbeta. PLIgamma was a 100-kDa glycoprotein containing 25-kDa and 20-kDa subunits and inhibited all of the PLA2s investigated equally, including Elapidae venom PLA2s (group I), Crotalidae and Viperidae venom PLA2s (group II) and honey-bee PLA2 (group III). From the N-terminal sequences of the two subunits, PLIgamma was found to be the same type of PLI that had been purified from Thailand cobra plasma.
authors.affiliation: Department of Biochemistry, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka 569-11, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ohkura
authors.forename: H
authors.initials: H
authors.lastname: Okuhara
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
mesh_terms: D017836:Agkistrodon / Q000097:blood*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003435:Crotalid Venoms / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010726:Phosphodiesterase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D010741:Phospholipases A / Q000037:antagonists & inhibitors* / Q000378:metabolism; D054467:Phospholipases A2; D011485:Protein Binding; D016415:Sequence Alignment; D017421:Sequence Analysis
chemical_list: D000596:Amino Acids; D003435:Crotalid Venoms; D010726:Phosphodiesterase Inhibitors; D010741:Phospholipases A; D054467:Phospholipases A2