Microheterogeneity of a male-specific rat hepatic cytochrome P-450: existence of three allozymic forms.
Preparations of hepatic cytochrome P-450 h [D. E. Ryan, et al. (1984) J. Biol. Chem. 259, 1239] and cytochrome P-450 2c [D. J. Waxman (1984) J. Biol. Chem. 259, 15481] from outbred Sprague-Dawley rats were analyzed using two-dimensional electrophoresis and in situ peptide mapping. Both preparations consisted of the same isozyme which was previously characterized as a developmentally regulated, male-specific cytochrome P-450 active in the 16 alpha-hydroxylation of steroids. Each preparation evidenced microheterogeneity which was shown, in part, to result from the existence of two genetically determined variant forms of cytochrome P-450 h/2c. Analyses of hepatic microsomes from several inbred strains of rat revealed that each was characterized by a single variant form of this isozyme, with some strains expressing a variant that was not present in Sprague-Dawley rats. Genetic crosses indicated that these electrophoretic variants represent allozymic forms of cytochrome P-450 h/2c which are codominantly expressed at a single autosomal locus. Additional microheterogeneity of each allozymic form of cytochrome P-450 h/2c was shown to result from a specific in vitro modification that may involve limited proteolysis near its C terminus by a microsome-bound protease.
D000483:Alleles; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis* / Q000235:genetics; D000072467:Cytochrome P450 Family 2; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000032:analysis* / Q000235:genetics; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D010446:Peptide Fragments / Q000032:analysis; D011487:Protein Conformation; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D039181:Steroid 16-alpha-Hydroxylase; D014357:Trypsin / Q000378:metabolism
D007527:Isoenzymes; D010446:Peptide Fragments; D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; C450279:CYP2C11 protein, rat; D000072467:Cytochrome P450 Family 2; D039181:Steroid 16-alpha-Hydroxylase; D014357:Trypsin