Functional expression of the cDNAs encoding rat 11 beta-hydroxylase [cytochrome P450(11 beta)] and aldosterone synthase [cytochrome P450(11 beta, aldo)].
Expression plasmids containing two cDNAs of a rat cytochrome P450(11 beta) family, pcP450(11 beta)-62 [Nonaka, Y., Matsukawa, N., Morohashi, K., Omura, T., Ogihara, T., Teraoka, H. & Okamoto, M. (1989) FEBS Lett. 255, 21-26] and pcP450(11 beta, aldo)-46 [Matsukawa, N., Nonaka, Y., Ying, Z., Higaki, J., Ogihara, T. & Okamoto, M. (1990) Biochem. Biophys. Res. Commun. 169, 245-252], were constructed and introduced into COS-7 cells by electroporation. Enzymatic activities of the expressed cytochromes P450(11 beta) and P450(11 beta, aldo) were determined by using 11-deoxycorticosterone, corticosterone, 18-hydroxy-11-deoxycorticosterone, 18-hydroxycorticosterone, or 19-hydroxy-11-deoxycorticosterone as a substrate. Cytochrome P450(11 beta) catalyzed 11 beta-, 18- and 19-hydroxylations of 11-deoxycorticosterone and 19-oxidation or 19-hydroxy-11-deoxycorticosterone at substantial rates, 18-hydroxylation of corticosterone at a very low rate, but no aldosterone production. Cytochrome P450(11 beta, aldo) catalyzed 11 beta- and 18-hydroxylations of 11-deoxycorticosterone, 18-hydroxylation of corticosterone and aldosterone production from 11-deoxycorticosterone or corticosterone. But neither 19-hydroxylation of 11-deoxycorticosterone nor 19-oxidation of 19-hydroxy-11-deoxycorticosterone was catalyzed by cytochrome P450(11 beta, aldo).
Nonaka
Y
Y
Department of Biochemistry, Osaka University Medical School, Japan.
Okamoto
M
M
D000325:Adrenodoxin / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D003001:Cloning, Molecular; D003345:Corticosterone / Q000378:metabolism; D019405:Cytochrome P-450 CYP11B2; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D007700:Kinetics; D008954:Models, Biological; D005810:Multigene Family; D010957:Plasmids; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013252:Steroid 11-beta-Hydroxylase / Q000235:genetics* / Q000378:metabolism; D013250:Steroid Hydroxylases / Q000235:genetics* / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis; D014162:Transfection
D011994:Recombinant Proteins; D013256:Steroids; D000325:Adrenodoxin; D004247:DNA; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D019405:Cytochrome P-450 CYP11B2; D013252:Steroid 11-beta-Hydroxylase; D003345:Corticosterone