title: Interspecies homology of cytochrome P-450: inhibition by anti-P-450-male antibodies of testosterone hydroxylases in liver microsomes from various animal species including man.
abstract: P-450-male is one of the male-specific forms of cytochrome P-450 in liver microsomes of adult rats and functions as testosterone 2 alpha- and 16 alpha-hydroxylases. The purpose of this study was to examine whether forms of cytochrome P-450 cross-reactive with anti-P-450-male antibodies are present in liver microsomes of other animal species, such as male and female mice, rabbits, guinea pigs, hamsters, dogs and humans. The antibodies cross-reacted with a protein(s) in the liver microsomes of all animal species to show one or more bands on nitrocellulose paper by Western blot peroxidase-anti-peroxidase staining analysis. Qualitative as well as quantitative species differences were noted in the testosterone hydroxylases. The antibodies inhibited 2 alpha-hydroxylase in male rats, 16 alpha-hydroxylase in male rats and male and female dogs, 7 alpha-hydroxylase in female rats and male and female mice and hamsters, and 15 alpha-hydroxylase in female mice and hamsters. No clear inhibition of 6 beta-hydroxylase, which was present in all animal species, was observed. These results indicate that forms of cytochrome P-450 that are immunochemically related with P-450-male catalyze the hydroxylation of testosterone at varying positions depending on the animal species, with the exception of 6 beta-hydroxylation, which may be catalyzed by a distinct form of cytochrome P-450.
authors.affiliation: Division of Analytical Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Miura
authors.forename: H
authors.initials: H
authors.lastname: Shimada
authors.forename: H
authors.initials: H
authors.lastname: Ohi
authors.forename: M
authors.initials: M
authors.lastname: Komori
authors.forename: T
authors.initials: T
authors.lastname: Kodama
authors.forename: T
authors.initials: T
authors.lastname: Kamataki
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology*; D001189:Aryl Hydrocarbon Hydroxylases; D015153:Blotting, Western; D006224:Cricetinae; D003429:Cross Reactions; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis* / Q000276:immunology; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D066298:In Vitro Techniques; D008297:Male; D008647:Mesocricetus; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D013045:Species Specificity; D039181:Steroid 16-alpha-Hydroxylase; D013250:Steroid Hydroxylases / Q000276:immunology / Q000378:metabolism*
chemical_list: D000906:Antibodies; D065607:Cytochrome P-450 Enzyme Inhibitors; D007074:Immunoglobulin G; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; D039181:Steroid 16-alpha-Hydroxylase; C022724:testosterone 7-alpha-hydroxylase, hamster