FATTY-ACID DISCRIMINATION AND OMEGA-HYDROXYLATION BY CYTOCHROME-P450 4A1 AND A CYTOCHROME P4504A1/NADPH-P450 REDUCTASE FUSION PROTEIN

Title

FATTY-ACID DISCRIMINATION AND OMEGA-HYDROXYLATION BY CYTOCHROME-P450 4A1 AND A CYTOCHROME P4504A1/NADPH-P450 REDUCTASE FUSION PROTEIN

Creator

Alterman M A; Chaurasia C S; Lu P; Hardwick J P; Hanzlik R P

Publisher

Archives of Biochemistry and Biophysics

Date

1995
1995-07

Description

The omega-hydroxylation of fatty acids by certain cytochrome P450 enzymes shows a degree of chain-length and regiospecificity which is remarkable in view of the conformational flexibility of these substrates, the strong similarity in properties among homologs, and the lack of polar groups (other than the carboxy terminus) with which to guide and strengthen enzyme-substrate interactions, To investigate the chemical basis for these features of omega-hydroxylation we designed and synthesized a series of lauric acid analogs and evaluated them as substrates and inhibitors of omega-hydroxylation catalyzed by cytochrome P4504A1 and a cytochrome P450 4A1/NADPH-P450 reductase fusion protein, Among n-alkanoic acids, lauric acid was found to have the optimum chain length for the fusion protein, as it does for native cytochrome P450 4A1, With both enzymes, chain shortening caused a precipitous drop in turnover while chain lengthening caused a gradual drop in turnover, The fusion protein omega-hydroxylated methyl laurate and lauryl alcohol about 1/10th as efficiently as lauric acid, but it did not hydroxylate lauramide, 10-Methoxydecanoic acid underwent O-demethylation (via omega-hydroxylation). The branched substrate 11-methyllauric acid was hydroxylated efficiently and selectively at the omega-position, In contrast, the cyclopropyl analog 11,12-methanolauric acid was not detectably hydroxylated, although it induced Type I binding spectrum and inhibited lauric acid omega-hydroxylation by 43% at equimolar concentrations, omega-(Imidazolyl)-decanoic acid induced a Type II heme-binding spectrum and was an especially potent inhibitor of lauric acid hydroxylation, Collectively these data suggest that the active site of cytochrome P450 4A1 has an elongated tubular shape of definite length (ca, 14 Angstrom) with a recognition site for polar groups (including but not limited to carboxyl) at its entrance and the (oxo)heme group at its terminus, (C) 1995 Academic Press, Inc.

Subject

Biochemistry & Molecular Biology; Biophysics; catalytic properties; cytochrome p450 4a1; escherichia-coli; expression; fusion protein; gene family; inhibition; lauric acid; mechanisms; omega-hydroxylation; purification

Format

Journal Article or Conference Abstract Publication

Search for Full-text

Users with a NEOMED Library login can search for full-text journal articles at the following url: https://libraryguides.neomed.edu/home

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

289-296

Issue

2

Volume

320

Citation

Alterman M A; Chaurasia C S; Lu P; Hardwick J P; Hanzlik R P, “FATTY-ACID DISCRIMINATION AND OMEGA-HYDROXYLATION BY CYTOCHROME-P450 4A1 AND A CYTOCHROME P4504A1/NADPH-P450 REDUCTASE FUSION PROTEIN,” NEOMED Bibliography Database, accessed May 16, 2021, https://neomed.omeka.net/items/show/8482.

Social Bookmarking