102029-73-2

Acetyl-coenzyme A (acetyl-CoA), the thioester of CoA (Item No. 16147) and acetic acid, is a pivotal molecule in biological systems. Foremost, it serves as a source of carbon for the Krebs cycle, for the synthesis of fatty acids, and for isoprenoid-based protein modifications. Acetyl-CoA also serves as an intermediate in oxidation of fatty acids and amino acids and is formed by the oxidative decarboxylation of pyruvate in mitochondria. It is an essential cofactor or substrate for acetyltransferases and acyltransferases, as in the post-translational modification of proteins and in the synthesis of the neurotransmitter acetylcholine.

Acetyl-Coenzyme A (Ac-CoA) is the end product of glycolysis and takes part in the Ac-CoA pathway, which is a metabolic pathway for carbon compounds. Ac-CoA is important in cholesterol synthesis. It also takes part in fatty acid biosynthesis and catabolism of polyamines like spermine and spermidine. A low level of Ac-CoA leads to a loss in glial cell and neuronal function. Ketone bodies and triglycerides give rise to Ac-CoA on hydrolysis and this indirectly leads to increased histone acetylation.

This key thiolester (FW = 809.57 g/mol; CAS 72-89-9) is the main C2 acyl donor in biosynthetic reactions in all living organisms. Acetyl-CoA is also an immediate product of fatty acid b-oxidation. The standard Gibbs free energy of hydrolysis (DG°’) of its thioester linkage is about –32.2 kJ/mol. Acetyl-CoA is water-soluble and stable in acid conditions (e.g., resisting hydrolysis for 15 minutes at pH 3.5-5 at 100°C), but readily hydrolyzed in alkaline solutions. Acetyl-S-CoA should be stored in a desiccator at +4°C. Its lmax at 260 nm (e = 16,400 M–1cm–1) at pH 7 is chiefly attributable to its adenine moiety. As is true for other thiolesters, the a-carbon of the acetyl– moiety is a weak carbon acid, forming reactive carbanion species CH2C (=O) -S-CoA. Target (s) : glucose-6-P dehydrogenase; pyruvate kinase; NAD (P) + transhydrogenase, AB-specific; enoyl-[acyl-carrier protein] reductase; pantothenate kinase; 3-hydroxy-3- methylglutaryl-CoA reductase; malonyl-CoA decarboxylase; oxaloacetate decarboxylase; methylmalonyl-CoA epimerase; pyruvate deydrogenase complex; succinyl-CoA synthetase; malyl-CoA lyase; phosphoketolase; aspartate 4 decarboxylase ; succinate:3-hydroxy-3-methylglutarate CoA-transferase; [3- methyl-2 oxobutanoate dehydrogenase (2-methylpropanoyl-transferring) ] phosphatase, or [branched-chain a-keto-acid dehydrogenase] phosphatase (19-21); phosphoprotein phosphatase (19-22); palmitoyl CoA hydrolase, or acyl-CoA hydrolase; (S) -methylmalonyl-CoA hydrolase; 3 hydroxyisobutyryl-CoA hydrolase; [protein-PII] uridylyltransferase ; adenylate kinase; glucose-1,6-bisphosphate synthase; cysteine synthase; 4-hydroxybenzoate nonaprenyltransferase, weakly inhibited; 2-methylcitrate synthase; decylcitrate synthase; anthocyanin 5-O-glucoside 6'''-O-malonyltransferase; anthocyanin 6''- O-malonyl-transferase; propionyl-CoA C2-trimethyltridecanoyl- transferase; b-ketoacyl-[acyl-carrier-protein] synthase I; [acyl- carrier-protein] S-malonyltransferase; and carnitine O- palmitoyltransferase .

Acetyl coenzyme A, the precursor of the acetate-malonare pathway, is a metabolite of extreme importance in both primary and secondary metabolism. In every living organism, there exists a metabolie pool of acetyl CoA which is continually replenished and depleted. Glycolysis and the catabolism of fatty acids and amino acids produce acetyl CoA, while this compound is the precursor of a host of primary and secondary metabolites, including fatty acids, terpenoids, steroids, polyketides, aromatic compounds and acetyl esters and amides. The conversion of acetyl CoA to citrate and other tricarboxylic acids leads to the formation of the amino acids and their products, such as the nucleic acids and alkaloids.
Acetyl CoA is also central to the catabolism of glucose and the fatty acids, which, through the tricarboxylic acid cycle, are the main reaction sequences producing the energy necessary for metabolie processes.
In plants, an enzyme, acetyl CoA synthetase, catalyses the formation of the thiol ester from acetate.