title: Anti-P450lpr antiserum inhibits specific monooxygenase activities in LPR house fly microsomes.
abstract: Monooxygenase activity in microsomes from the LPR strain of house fly (Musca domestica L.) was inhibited by anti-P450lpr, and antiserum specific for house fly cytochrome P450lpr. Anti-P450lpr did not inhibit house fly cytochrome P450 reductase or rat cytochrome P450 monooxygenase assays, consistent with specific inhibition of P450lpr. Anti-P450lpr inhibited the ability of cytochrome P450 reductase to reduce carbon monoxide treated LPR microsomal cytochrome P450, up to 49% of the total, showing that inhibition of cytochrome P450 reduction is the major mechanism of inhibition. Anti-P450lpr inhibited 98% of methoxyresorufin-O-demethylase activity and all the benzo(a)pyrene hydroxylase activity in LPR microsomes, but none of the pentoxyresorufin-O-dealkylase activity. The antiserum partially inhibited ethoxyresorufin-O-dealkylase and ethoxycoumarin-O-dealkylase activity. These results demonstrate that methoxyresourfin-O-demethylase activity and benzo(a)pyrene hydroxylase activity are characteristic substrates for P450lpr activity in the LPR strain of house fly.
authors.affiliation: Department of Entomology, Cornell University, Ithaca, New York 14853.
authors.forename: G D
authors.initials: GD
authors.lastname: Wheelock
authors.forename: J G
authors.initials: JG
authors.lastname: Scott
mesh_terms: D015660:7-Alkoxycoumarin O-Dealkylase / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000378:metabolism; D001667:Binding, Competitive; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000276:immunology / Q000378:metabolism; D006793:Houseflies; D008861:Microsomes / Q000201:enzymology*; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000906:Antibodies; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; C076307:methoxyresorufin-O-demethylase; D015660:7-Alkoxycoumarin O-Dealkylase; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1