title: Multiple effects of isoproterenol on horse plasma cholinesterase.
abstract: Isoproterenol inhibits the hydrolysis of butyrylthiocholine by horse plasma cholinesterase, while it stimulates the hydrolysis of p-nitrophenyl butyrate. The inhibition pattern obtained for butyrylthiocholine is consistent with a dimeric model for the enzyme showing negative cooperativity. The kinetics of inhibition point to a dissociative effect of isoproterenol, superimposed on its competitive inhibitory action. The hydrolysis of p-nitrophenyl butyrate is not sensitive to changes in the subunit composition of the enzyme.
authors.forename: Z
authors.initials: Z
authors.lastname: Söylemez
authors.forename: I
authors.initials: I
authors.lastname: Ozer
mesh_terms: D000818:Animals; D002800:Cholinesterase Inhibitors / Q000097:blood*; D006736:Horses; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D008433:Mathematics; D008954:Models, Biological; D011485:Protein Binding; D013379:Substrate Specificity
chemical_list: D002800:Cholinesterase Inhibitors; D007545:Isoproterenol