Purification and characterization of three male-specific and one female-specific forms of cytochrome P-450 from rat liver microsomes.

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Matsumoto T, Emi Y, Kawabata S, Omura T

Purification and characterization of three male-specific and one female-specific forms of cytochrome P-450 from rat liver microsomes.

J Biochem. 1986 Nov;100(5):1359-71.

PubMed ID

2434473 [ View in PubMed

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Abstract

Three forms of cytochrome P-450, tentatively designated P-450(M-1), P-450(M-2), and P-450(M-3), and one form of cytochrome P-450, P-450(F-1), were purified from the liver microsomes of untreated male and female rats, respectively. Each purified form of the cytochrome showed a single protein band on SDS-polyacrylamide gel electrophoresis, and gave a minimum molecular weight of 51,000 for P-450(M-1), 48,000 for P-450(M-2), 49,000 for P-450(M-3), and 50,000 for P-450(F-1). The carbon monoxide-difference spectra of reduced P-450(M-1), P-450(M-2), P-450(M-3), and P-450(F-1) showed an absorption maximum at 451, 451, 448, and 449 nm, respectively. Judging from the absolute absorption spectra, the four forms of cytochrome P-450 were of low-spin type in the oxidized forms. The antibodies against P-450(M-2) did not crossreact with the other forms in the Ouchterlony double diffusion test, whereas the immunodiffusion test showed immunocrossreactivity between P-450(M-1) and P-450(F-1), P-450(M-1) and P-450(M-3), and P-450(M-3) and P-450(F-1). The NH2-terminal amino acid sequences of the four forms confirmed that they were different molecular species, although significant homology was noticed among P-450(M-1), P-450(M-3), and P-450(F-1). The quantitation of P-450(M-1) and P-450(F-1) in liver microsomes by quantitative immunoprecipitation confirmed that these two forms of cytochrome P-450 were developmentally induced in male and female rats, respectively. P-450(M-2) was also developmentally induced in male rats. In a reconstituted system containing NADPH and NADPH-cytochrome P-450 reductase, P-450(M-1) oxidized benzphetamine at a high rate, whereas the other forms had low activity toward benzphetamine. None of the four forms showed high activity toward benzo(a)pyrene. P-450(M-1) catalyzed the hydroxylation testosterone at the 16 alpha and 2 alpha positions, whereas P-450(M-2) catalyzed the 15 alpha hydroxylation of the same substrate.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Benzphetamine	NADPH--cytochrome P450 reductase	Protein	Humans	Unknown	Substrate	Details

Polypeptides

Name	UniProt ID
Cytochrome P450 2A2	P15149	Details
Cytochrome P450 2C11	P08683	Details