title: A novel binding assay for phospholipase A2.
abstract: We have devised a rapid and simple assay for estimating the binding of pancreatic phospholipase A2 to a bilayer lipid membrane. The binding was observed to be extremely rapid at 37 degrees and was absolutely dependent upon Ca2+. Amongst several drugs known to inhibit the catalytic activity of phospholipase only mepacrine at high concentrations (500 microM) and chlorpromazine (100 microM) were active. Treatment of the enzyme with p-bromophenacylbromide did not inhibit binding. Several alcohols potentiated binding whereas detergents tended to inhibit. Amongst several purified proteins tested, only the steroid-induced anti-phospholipase protein lipocortin prevented binding. The use of this assay in screening for antiphospholipase agents is discussed.
authors.affiliation: Pharmacology Group, University of Bath, Claverton Down, U.K.
authors.forename: S H
authors.initials: SH
authors.lastname: Peers
authors.forename: R D
authors.initials: RD
authors.lastname: Taylor
authors.forename: R J
authors.initials: RJ
authors.lastname: Flower
mesh_terms: D001665:Binding Sites; D001667:Binding, Competitive; D002118:Calcium / Q000502:physiology; D004926:Escherichia coli; D007700:Kinetics; D008024:Ligands; D008566:Membranes / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2
chemical_list: D008024:Ligands; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium