title: Steric course of reaction catalyzed by the enoyl acyl-carrier-protein reductase of Escherichia coli.
abstract: The steric course of the reaction catalyzed by Escherichia coli enoyl acyl-carrier-protein reductase was studied. 1. trans-2-[2-2H1]Decenoic and trans-2-[3-2H1]decenoic acids were synthesized and converted to the corresponding decenoyl thiol esters with CoA or acyl carrier protein. These deuterium-labeled decenoyl thiol esters were incubated with purified enoyl acyl-carrier-protein reductase in the presence of NADPH or NADH. 2. The unlabeled trans-2-decenoyl thiol esters were incubated with enoyl acyl-carrier-protein reductase in the presence of (4S)-[4-2H1]NADH. The unlabeled decenoyl thiol esters were also incubated with the enzyme in 2H2O. The decanoic acids formed in the above incubations were extracted and subjected to the action of acyl-CoA oxidase, which had been previously shown to catalyze the anti elimination of the pro-2R and pro-3R hydrogens of acyl-CoA. The resulting products, 2-decenoyl-CoAs, were converted to methyl esters and their deuterium contents were analyzed by gas chromatography/mass spectrometry. The results suggested that the reduction catalyzed by E. coli enoyl acyl-carrier-protein reductase occurs by a syn addition of hydrogen via a 2-Re, 3-Si attack on the double bond.
mesh_terms: D000213:Acyl Carrier Protein / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D003652:Decanoic Acids; D050753:Enoyl-(Acyl-Carrier-Protein) Reductase (NADH); D004926:Escherichia coli / Q000201:enzymology*; D004952:Esters; D005231:Fatty Acids, Unsaturated; D008401:Gas Chromatography-Mass Spectrometry; D013058:Mass Spectrometry; D010088:Oxidoreductases / Q000378:metabolism*; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D000213:Acyl Carrier Protein; D003652:Decanoic Acids; D004952:Esters; D005231:Fatty Acids, Unsaturated; D010088:Oxidoreductases; D000445:Aldehyde Oxidoreductases; C027014:acetaldehyde dehydrogenase (acylating); D050753:Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)