TY - JOUR
T1 - Regiospecific hydroxylation of lauric acid at the (ω-1) position by hepatic and kidney microsomal cytochromes P-450 from rainbow trout
AU - Williams, David E.
AU - Okita, Richard T.
AU - Buhler, Donald R.
AU - Siler Masters, Bettie Sue
N1 - Funding Information:
r This researc:h was supported by USPHS Grant GM 31296 (B.S.S.M. and R.T.O.), NIH Grant ES-00210 (D.R.B.), and NIEHS Grant 01985. ’ To whom correspondence should be addressed.
PY - 1984/6
Y1 - 1984/6
N2 - Microsomes from liver or kidney of untreated rainbow trout hydroxylated lauric acid specifically at the (ω-1) position. Turnover numbers for liver (2.72 min-1) and kidney (14.1 min-1) were decreased seven- and twofold, respectively, following treatment with β-naphthoflavone. Laurate hydroxylation activity from untreated trout hepatic microsomes was sensitive to inhibition by SKF-525A, but was not sensitive to metyrapone and only partially inhibited by α-naphthoflavone. The temperature optimum of laurate (ω-1) hydroxylation in trout liver microsomes was 25-30 °C. The Km and Vmax for (ω-1)-hydroxylaurate formation was 50 μm and 1.63 nmol min-1 mg-1, respectively, in liver and 20 μm and 3.95 nmol min-1 mg-1, respectively, in kidney from untreated trout microsomes. (ω-1) Hydroxylation of laurate, in both liver and kidney microsomes, was sensitive to an antibody raised against a previously purified cytochrome P-450 isozyme (LM2) of trout liver microsomes, which has been shown to be active towards aflatoxin B1. Antibody to the major isozyme of cytochrome P-450 (LM4b, active towards benzo(a)pyrene) induced by β-naphthoflavone did not inhibit (ω-1) hydroxylation of laurate in microsomes from untreated or ω-naphthoflavone-treated trout.
AB - Microsomes from liver or kidney of untreated rainbow trout hydroxylated lauric acid specifically at the (ω-1) position. Turnover numbers for liver (2.72 min-1) and kidney (14.1 min-1) were decreased seven- and twofold, respectively, following treatment with β-naphthoflavone. Laurate hydroxylation activity from untreated trout hepatic microsomes was sensitive to inhibition by SKF-525A, but was not sensitive to metyrapone and only partially inhibited by α-naphthoflavone. The temperature optimum of laurate (ω-1) hydroxylation in trout liver microsomes was 25-30 °C. The Km and Vmax for (ω-1)-hydroxylaurate formation was 50 μm and 1.63 nmol min-1 mg-1, respectively, in liver and 20 μm and 3.95 nmol min-1 mg-1, respectively, in kidney from untreated trout microsomes. (ω-1) Hydroxylation of laurate, in both liver and kidney microsomes, was sensitive to an antibody raised against a previously purified cytochrome P-450 isozyme (LM2) of trout liver microsomes, which has been shown to be active towards aflatoxin B1. Antibody to the major isozyme of cytochrome P-450 (LM4b, active towards benzo(a)pyrene) induced by β-naphthoflavone did not inhibit (ω-1) hydroxylation of laurate in microsomes from untreated or ω-naphthoflavone-treated trout.
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U2 - 10.1016/0003-9861(84)90414-4
DO - 10.1016/0003-9861(84)90414-4
M3 - Article
C2 - 6732245
AN - SCOPUS:0021254185
VL - 231
SP - 503
EP - 510
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -