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.

Acyl-CoA binding and acylation of UDP-glucuronosyltransferase isoforms of rat liver: their effect on enzyme activity.

Abstract: When [14C]arachidonoyl-CoA was incubated with crude extracts of rat liver microsomes, [14C]arachidonic acid was incorporated into many proteins, suggesting that modification of these proteins with fatty acid, i.e. acylation, occurred. Using a [14C]arachidonyl-CoA labelling assay, 50 and 53 kDa proteins were purified from rat liver microsomes to near homogeneity by sequential chromatography on Red-Toyopearl, hydroxyapatite, heparin-Toyopearl, Blue-Toyopearl and UDP-hexanolamine-agarose. Acylation of the 50 and 53 kDa proteins occurred in the absence of any other protein, suggesting that these molecules catalyse autoacylation. The acylation was dependent on the length of the incubation period and the concentration of [14C]arachidonoyl-CoA. The 50 and 53 kDa proteins also had acyl-CoA-binding activity; initial rates of acyl-CoA binding and acylation were 0.25 and 0.004 min-1 respectively. The proteins also had weak but distinct acyl-CoA-hydrolysing activity (0.006 min-1). These results suggest that the proteins catalysed the sequential reactions of binding to acyl-CoA, autoacylation, and hydrolysis of fatty acid. N-terminal amino acid sequencing analysis showed these proteins to be UDP-glucuronosyltransferase (UDPGT) isoforms. UDPGT activity was inhibited by arachidonoyl-CoA. These results suggest that binding of acyl-CoA and acylation of UDPGT isoforms regulate the enzyme activities, implying a possible novel function for fatty acyl-CoA in glucuronidation, which is involved in the metabolism of drugs, steroids and bilirubin.

Complex Formation Between Mycobacterial Polysaccharides and Fatty Acyl-CoA Derivatives

Abstract: The mycobacterial polysaccharides MMP and MGLP, which contain numerous O-methyl-sugar residues, markedly stimulate fatty acid synthesis catalyzed by a multienzyme complex from Mycobacterium phlei [Ilton, M. et al. (1971) Proc. Nat. Acad. Sci. USA 68, 87-91]. When aqueous solutions containing MMP or MGLP and palmitoyl-CoA were chromatographed on Sephadex G-75 under conditions that widely separate the individual components, polysaccharide and fatty acyl-CoA were eluted in a single peak, indicating formation of a molecular complex. Similarly, the mycobacterial polysaccharides associate with the CoA derivatives of C18, C20, and C22 acids to yield complexes containing maximally 1 mol of fatty acyl-CoA per mol of polysaccharide. The formation of these novel complexes may result from hydrophobic interactions between the paraffin chains of the acyl-CoA derivatives and O-methyl-sugar residues of the polysaccharides.