Electron-transfer mechanism associated with fatty acid desaturation catalyzed by liver microsomes

Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation Pub Date : 1966-10-17 DOI:10.1016/0926-6593(66)90137-8

Nozomu Oshino, Yoshio Imai, Ryo Sato

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引用次数: 234

Abstract

Suitable assay conditions are described for the NADPH-dependent oxidative desaturation of stearyl-CoA by rat-liver microsomes.

NADH is an even more effective electron donor than NADPH. Ascorbate at high concentrations also acts as a donor, but with low efficiency. Unlike the NADPH-dependent drug hydroxylations, the desaturation reaction does not seem to involve the microsomal hemoprotein P-450. Instead, a hitherto unknown cyanide-sensitive factor appears to be involved in the desaturation mechanism, regardless of the electron donors employed. The microsomal NADPH-specific flavoprotein with a cytochrome $c$ reductase activity seems to participate, not only in the NADPH-dependent drug hydroxylations, but also in the NADPH-supported desaturation. Microsomal oxidation of methanol, which requires NADPH and is sensitive to cyanide, appears to be catalyzed by a mechanism which differs from that involved in desaturation.

On the basis of these findings the electron-transfer mechanisms associated with these microsomal reactions are discussed.

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肝微粒体催化脂肪酸去饱和的电子转移机制

本文描述了大鼠肝微粒体对铁酰辅酶a nadph依赖性氧化去饱和的适宜实验条件。NADH是比NADPH更有效的电子供体。高浓度的抗坏血酸也起供体作用，但效率较低。与nadph依赖的药物羟基化不同，去饱和反应似乎不涉及微粒体血红蛋白P-450。相反，一种迄今为止未知的氰化物敏感因子似乎参与了脱饱和机制，而不管所使用的电子供体是什么。具有细胞色素c还原酶活性的微粒体nadph特异性黄蛋白似乎不仅参与nadph依赖的药物羟基化，而且参与nadph支持的去饱和。微粒体甲醇氧化需要NADPH并且对氰化物敏感，其催化机制似乎不同于去饱和过程。在这些发现的基础上，讨论了与这些微粒体反应相关的电子转移机制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation

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