title: Lys-49-phospholipases A2 as active enzyme for beta-arachidonoyl phospholipid bilayer membranes.
abstract: Phospholipases A2 containing Lys-49 have been reported to be extremely weak or inactive as enzyme. We have recently shown that basic proteins I and II (BP-I and BP-II), Lys-49-PLA2s isolated from the venom of Trimeresurus flavoviridis (Habu snake), are potent to hydrolyze the arachidonate of 2-arachidonoyl-1-stearoyl-L-3-phosphatidylcholine (ASPC) in bilayer vesicles. In order to ensure such enzymatic activity of Lys-49-PLA2s, two other Lys-49-PLA2s from different snake venoms, myotoxin II (from Bothrops asper) and App-K49 (form Agkistrodon piscivorus piscivorus), were examined. Myotoxin II was found to be very active, even more potent than BP-II, liberating about 80% of arachidonic acid from liposomes. App-K49 was also active (about 50%) for ASPC liposomes. They were very weak or almost inactive for ASPC micelles and monomers. All these Lys-49-PLA2s were inactive for ASPC liposomes in the absence of Ca2+. These results clearly demonstrated that Lys-49-PLA2s are the enzymes to hydrolyze the C2-ester bond of ASPC in bilayer membranes.
authors.affiliation: Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Shimohigashi
authors.forename: T
authors.initials: T
authors.lastname: Chiwata
authors.forename: A
authors.initials: A
authors.lastname: Tani
authors.forename: T
authors.initials: T
authors.lastname: Chijiwa
authors.forename: B
authors.initials: B
authors.lastname: Lomonte
authors.forename: M
authors.initials: M
authors.lastname: Ohno
mesh_terms: D000595:Amino Acid Sequence; D001095:Arachidonic Acids / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D054501:Group II Phospholipases A2; D008051:Lipid Bilayers / Q000378:metabolism*; D008081:Liposomes / Q000378:metabolism; D008823:Micelles; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D030162:Reptilian Proteins
chemical_list: D001095:Arachidonic Acids; D008051:Lipid Bilayers; D008081:Liposomes; D008823:Micelles; D009498:Neurotoxins; D010743:Phospholipids; D030162:Reptilian Proteins; D010741:Phospholipases A; D054501:Group II Phospholipases A2; C076780:myotoxin I