{"title":"Electron-transfer mechanism associated with fatty acid desaturation catalyzed by liver microsomes","authors":"Nozomu Oshino, Yoshio Imai, Ryo Sato","doi":"10.1016/0926-6593(66)90137-8","DOIUrl":null,"url":null,"abstract":"<div><p>Suitable assay conditions are described for the NADPH-dependent oxidative desaturation of stearyl-CoA by rat-liver microsomes.</p><p>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 <span><math><mtext>c</mtext></math></span> 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.</p><p>On the basis of these findings the electron-transfer mechanisms associated with these microsomal reactions are discussed.</p></div>","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1966-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90137-8","citationCount":"234","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0926659366901378","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
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 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.