Acyl-CoA

About: Acyl-CoA is a research topic. Over the lifetime, 527 publications have been published within this topic receiving 25134 citations. The topic is also known as: Acyl Coenzyme A.

Phosphatidyl choline fatty acid remodeling in the hepatic cell nuclei

Abstract: This study was performed to determine whether fatty acids incorporated into liver cell nuclei phosphatidylcholine (PtdCho) could be remodeled in the isolated nuclear. For this reason, rat liver cell nuclei were incubated in vitro with [1- 14 C]20:4n-6-CoA. PtdCho molecular species with the highest specific activity had an unsaturated fatty acid at sn- 1 and sn- 2 positions (20:4-20:4>>18:2-20:4>18:1-20:4). 16:0-20:4 and 18:0-20:4 PtdChos showed a minor specific activity. When labeled nuclei were reincubated in the absence of labeled substrate with the addition of cytosol, ATP and CoA, the specific activity of 20:4-20:4, 18:2-20:4 and 18:1-20:4 species decreased, while that of 16:0-20:4 and 18:0-20:4 increased. In conclusion, the asymmetric fatty acid distribution of saturated fatty acids at sn- 1 position, and unsaturated fatty acids at sn- 2 position of nuclear PtdCho molecular species was re-established by an acyl-CoA-dependent remodeling process.

Butyryl Coenzyme A Dehydrogenase: Studies on the Specificity of the Formation of Acyl Coenzyme A Complexes with Long-Wavelength Absorption

Abstract: Further studies of butyryl CoA dehydrogenase show that the enzyme forms tight complexes with long-wavelength absorption bands upon addition of α, β-unsaturated alicyclic carboxylic acyl CoA compounds. As in the straight chain series, the size of the acyl moiety is critical. The thiol portion by contrast determines neither whether a long-wavelength band is formed nor the wavelength of maximum absorption if such a band is present. It does however markedly affect the dissociation constant. Unusual features of the acid stability of the acyl CoA found on the native green form of the enzyme are also reported.

One-step synthesis of radioactive acyl-CoA and acylcarnitines using rat liver mitochondrial outer membrane as enzyme source.

Abstract: Rat liver mitochondrial outer membrane enriched preparations have proven to be a convenient enzyme source for synthesizing coenzyme A (CoA) and carnitine esters of radioactive fatty acids. These membranes are simple to isolate and they retain acyl-CoA ligase and carnitine palmitoyltransferase activities well upon storage. Enzyme purification is not required. A novel aspect of the present procedure is that the same enzymatic incubation step allows both the acyl-CoA and the acylcarnitine esters to be obtained simulataneously when carnitine is present, but produces acyl-CoA ester only when carnitine is not included. Under the conditions described, the conversion of [1-14C]octanoic acid to the respective esters was about 95%; the corresponding figure for [1-14C]palmitic acids was over 70%. The procedure seems suitable for synthesizing the labeled CoA and carnitine esters from a variety of radioactive fatty acids.

Acyl-CoA thioesterases belong to a novel gene family of peroxisome proliferator-regulated enzymes involved in lipid metabolism

Abstract: Acyl-CoA thioesterases hydrolyze acyl-CoAs to the corresponding free fatty acid plus coenzyme A. The activity is strongly induced in rat and mouse liver after feeding the animals peroxisome proliferators (PPs). To elucidate the role of these enzymes in lipid metabolism, the authors have cloned the cDNAs corresponding to the inducible cytosolic and mitochondrial type I enzymes (CTE-I and MTE-I), and studied tissue expression and nutritional regulation of expression of the mRNAs in mice. The constitutive expression of both mRNAs was low in liver, with CTE-I expressed mainly in kidney and brown adipose tissue, and MTE-I expressed in brown adipose tissue and heart. As expected, the expression in liver of both the CTE-I and MTE-I mRNAs were strongly induced (> 50-fold) by treatment with clofibrate. A similar level of induction was observed by fasting and a time-course study showed that the CTE-I and MTE-I mRNAs were increased already at 6 h after removal of the diet. Refeeding normal chow diet to mice fasted for 24 h normalized the mRNA levels with a T1/2 of about 3-4 h. Feeding mice a fat-free diet further decreased the expression, possibly indicating repression of expression. The strong expression of MTE-I and CTE-I in the heart was increased about 10-fold by fasting. To further characterize these highly regulated enzymes, the authors have cloned the corresponding genes and promoter regions. The structures of the two genes were found to be very similar, consisting of three exons and two introns. Exon-intron borders conform to general consensus sequences, and, especially, the first exon appears to be highly conserved. The promoter regions of both the CTE-I and MTE-I genes contain putative PP response elements, suggesting an involvement of PP-activated receptors in the regulation of these genes.