MECHANISM OF oc,B-DEHYDROGENATION OF FATTY ACID CoA DERIVATIVES BY FLAVIN ENZYMES
نویسنده
چکیده
From the mechanistic point of view, the dehydrogenation of fatty acids (as CoA esters), and of a few other biologically relevant molecules, such as succinate, is unique in that it involves the rupture of two kinetically stable C-H bonds. This is contrary to the flavin dependent dehydrogenation of most other substrates, as has been discussed elsewhere (1,2). Generally a single C-H bond, which is flanked by a (kinetically) labile -X-H (or X-) group (X 0 dehydrogenation is as follows: or NR), is broken during catalysis. The stereochemistry of is pro-2R, pro-3R, trans (3,4), and its minimal formulation
منابع مشابه
Acyl-CoA dehydrogenases. A mechanistic overview.
Acyl-CoA dehydrogenases constitute a family of flavoproteins that catalyze the alpha,beta-dehydrogenation of fatty acid acyl-CoA conjugates. While they differ widely in their specificity, they share the same basic chemical mechanism of alpha,beta-dehydrogenation. Medium chain acyl-CoA dehydrogenase is probably the best-studied member of the class and serves as a model for the study of catalytic...
متن کاملTransformation of Rapeseed (Brassica napus L.) Plants with Sense and Antisense Constructs of the Fatty Acid Elongase Gene
The biosynthetic pathways of saturated and unsaturated fatty acids consist of many steps controlled by various enzymes. One of the methods for improving oil quality is to change the fatty acid profile through genetic manipulation which requires isolation and characterization of the genes and other cis-acting elements, such as the promoter, involved in fatty acid biosynthesis. b-ketoacyl-CoA syn...
متن کاملThe effect of vitamin B12 deprivation on the enzymes of fatty acid synthesis.
The enzymes of fatty acid synthesis from liver and brain in normal and Blz-deprived rats were studied. Both total and specific activities of fatty acid synthetase and acetyl coenzyme A carboxylase were 2to 5-fold greater in Blz deprivation than in the normal state. The presence of excess activators in the BIp-deprived rat or an excess inhibitor in the normal rat was not found by serial admixtur...
متن کاملDehydrogenation Mechanism in Flavoprotein Catalysis
I "C -X-H+Acc(ox)--> C =X+Acc(red)H 2 I / H This type of reaction should be differentiated from the oxygenase reaction, in which the substrate electrons are transferred directly to oxygen. The limiting chemical step of the dehydrogenation, i.e., the rupture of the kinetically stable substrate C-H bond, is catalyzed by enzymes which have either pyridine nucleotide, pyridoxal-phosphate, flavin-, ...
متن کاملAnalysis of pristanic acid b -oxidation intermediates in plasma from healthy controls and patients affected with peroxisomal disorders by stable isotope dilution gas chromatography mass spectrometry
In this paper we report the development of highly sensitive, selective, and accurate stable isotope dilution gas chromatography negative chemical ionization mass spectrometry (GC-NCI-MS) methods for quantification of peroxisomal b -oxidation intermediates of pristanic acid in human plasma: 2,3-pristenic acid, 3-hydroxypristanic acid, and 3-ketopristanic acid. The carboxylic groups of the interm...
متن کامل