[Involvement of electron transfer system on microsomal fatty acid chain elongation]. 1983

M Nagao

It has been demonstrated that liver microsomal electron transfer system participates in lipid metabolism, fatty acid desaturation or cholesterol biosynthesis. Recent reports have shown the participation of cytochrome b5 and NADPH-cytochrome P-450 reductase (FPT) on NADPH-initiated microsomal fatty acid chain elongation. However, it remains unclear in which reductive step of the elongation system they participate. In the present study, the author examined carefully the composition of microsomal chain elongation products in the presence or absence of anti-cytochrome b5 or anti-FPT IgG. The reaction products from [2-14C] malonyl-CoA and palmitoyl-CoA by rat liver microsomes were mainly 18 : 0 and 18 : 1. However, when anti-b5 or anti-FPT IgG was included in this system, not only total chain elongation was suppressed but also a new radioactive product was appeared significantly (20-30%) besides elongated fatty acids. The new product was identified as 2-heptadecanone derived from beta-ketostearic acid, which increased depending upon the amounts of antibodies added. These results suggest that cytochrome b5 and FPT participate in the first reductive step, conversion from beta-ketostearoyl-CoA to beta-hydroxystearoyl-CoA, in the microsomal chain elongation system.

UI MeSH Term Description Entries
D008297 Male Males
D008316 Malonyl Coenzyme A A coenzyme A derivative which plays a key role in the fatty acid synthesis in the cytoplasmic and microsomal systems. Malonyl CoA,CoA, Malonyl,Coenzyme A, Malonyl
D008862 Microsomes, Liver Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough. Liver Microsomes,Liver Microsome,Microsome, Liver
D009245 NADH Dehydrogenase A flavoprotein and iron sulfur-containing oxidoreductase that catalyzes the oxidation of NADH to NAD. In eukaryotes the enzyme can be found as a component of mitochondrial electron transport complex I. Under experimental conditions the enzyme can use CYTOCHROME C GROUP as the reducing cofactor. The enzyme was formerly listed as EC 1.6.2.1. NADH Cytochrome c Reductase,Diaphorase (NADH Dehydrogenase),NADH (Acceptor) Oxidoreductase,NADH Cytochrome c Oxidoreductase,Dehydrogenase, NADH
D009251 NADPH-Ferrihemoprotein Reductase A flavoprotein that catalyzes the reduction of heme-thiolate-dependent monooxygenases and is part of the microsomal hydroxylating system. EC 1.6.2.4. Cytochrome P-450 Reductase,Ferrihemoprotein P-450 Reductase,NADPH Cytochrome P-450 Oxidoreductase,NADPH Cytochrome P-450 Reductase,NADPH Cytochrome c Reductase,Cytochrome P-450 Oxidase,Cytochrome P450 Reductase,Ferrihemoprotein P450 Reductase,NADPH Cytochrome P450 Oxidoreductase,NADPH Cytochrome P450 Reductase,NADPH-Cytochrome P450 Reductase,NADPH-P450 Reductase,Cytochrome P 450 Oxidase,Cytochrome P 450 Reductase,Ferrihemoprotein P 450 Reductase,NADPH Cytochrome P 450 Oxidoreductase,NADPH Cytochrome P 450 Reductase,NADPH Ferrihemoprotein Reductase,NADPH P450 Reductase,Oxidase, Cytochrome P-450,P-450 Oxidase, Cytochrome,P450 Reductase, Cytochrome,P450 Reductase, NADPH-Cytochrome,Reductase, Cytochrome P-450,Reductase, Cytochrome P450,Reductase, Ferrihemoprotein P-450,Reductase, Ferrihemoprotein P450,Reductase, NADPH-Cytochrome P450,Reductase, NADPH-Ferrihemoprotein,Reductase, NADPH-P450
D010171 Palmitoyl Coenzyme A A fatty acid coenzyme derivative which plays a key role in fatty acid oxidation and biosynthesis. Palmitoyl CoA,Hexadecanoyl CoA,Palmityl CoA,CoA, Hexadecanoyl,CoA, Palmitoyl,CoA, Palmityl,Coenzyme A, Palmitoyl
D003573 Cytochrome b Group Cytochromes (electron-transporting proteins) with protoheme (HEME B) as the prosthetic group. Cytochromes Type b,Cytochromes, Heme b,Group, Cytochrome b,Heme b Cytochromes,Type b, Cytochromes,b Cytochromes, Heme,b Group, Cytochrome
D005227 Fatty Acids Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed) Aliphatic Acid,Esterified Fatty Acid,Fatty Acid,Fatty Acids, Esterified,Fatty Acids, Saturated,Saturated Fatty Acid,Aliphatic Acids,Acid, Aliphatic,Acid, Esterified Fatty,Acid, Saturated Fatty,Esterified Fatty Acids,Fatty Acid, Esterified,Fatty Acid, Saturated,Saturated Fatty Acids
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D015786 Cytochromes b5 Cytochromes of the b group that are found bound to cytoplasmic side of ENDOPLASMIC RETICULUM. They serve as electron carrier proteins for a variety of membrane-bound OXYGENASES. They are reduced by the enzyme CYTOCHROME-B(5) REDUCTASE. Apocytochrome b5,Cytochrome b-5,Cytochrome b5,Ferricytochrome b5,Cytochrome b 5

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