Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. All genomes sequenced to date encode enzymes that use coenzyme A as a substrate, and around 4% of cellular enzymes use it (or a thioester) as a substrate. In humans, CoA biosynthesis requires cysteine, pantothenate (vitamin B5), and adenosine triphosphate (ATP).
Acetoacetic acid is the organic compound with the formula CH3COCH2COOH. It is the simplest beta-keto acid, and like other members of this class, it is unstable. The methyl and ethyl esters, which are quite stable, are produced on a large scale industrially as precursors to dyes. Acetoacetic acid is a weak acid.
Acetoacetyl CoA is the precursor of HMG-CoA in the mevalonate pathway, which is essential for cholesterol biosynthesis. It also takes a similar role in the ketone bodies synthesis (ketogenesis) pathway of the liver. In the ketone bodies digestion pathway, it is no longer associated with having HMG-CoA as a product or as a reactant.
In enzymology, an acetoacetyl-CoA reductase (EC 1.1.1.36) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-hydroxybutyryl-CoA dehydrogenase (EC 1.1.1.157) is an enzyme that catalyzes the chemical reaction
In enzymology, a butanal dehydrogenase (EC 1.2.1.57) is an enzyme that catalyzes the chemical reaction
In enzymology, an isobutyryl-CoA mutase is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-oxoacid CoA-transferase is an enzyme that catalyzes the chemical reaction
In enzymology, an acetate CoA-transferase is an enzyme that catalyzes the chemical reaction
In enzymology, an acetoacetate—CoA ligase is an enzyme that catalyzes the chemical reaction
Butyrate—CoA ligase, also known as xenobiotic/medium-chain fatty acid-ligase (XM-ligase), is an enzyme that catalyzes the chemical reaction:
The enzyme acetoacetyl-CoA hydrolase (EC 3.1.2.11) catalyzes the reaction
Butyryl-coenzyme A is the coenzyme A-containing derivative of butyric acid. It is acted upon by butyryl-CoA dehydrogenase and an intermediary compound of ABE fermentation.
In enzymology, an acetyl-CoA C-acetyltransferase is an enzyme that catalyzes the chemical reaction
In molecular biology, hydroxymethylglutaryl-CoA synthase or HMG-CoA synthase EC 2.3.3.10 is an enzyme which catalyzes the reaction in which acetyl-CoA condenses with acetoacetyl-CoA to form 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA). This reaction comprises the second step in the mevalonate-dependent isoprenoid biosynthesis pathway. HMG-CoA is an intermediate in both cholesterol synthesis and ketogenesis. This reaction is overactivated in patients with diabetes mellitus type 1 if left untreated, due to prolonged insulin deficiency and the exhaustion of substrates for gluconeogenesis and the TCA cycle, notably oxaloacetate. This results in shunting of excess acetyl-CoA into the ketone synthesis pathway via HMG-CoA, leading to the development of diabetic ketoacidosis.
In enzymology, a phosphate butyryltransferase is an enzyme that catalyzes the chemical reaction
3-oxoacid CoA-transferase 1 (OXCT1) is an enzyme that in humans is encoded by the OXCT1 gene. It is also known as succinyl-CoA-3-oxaloacid CoA transferase (SCOT). Mutations in the OXCT1 gene are associated with succinyl-CoA:3-oxoacid CoA transferase deficiency. This gene encodes a member of the 3-oxoacid CoA-transferase gene family. The encoded protein is a homodimeric mitochondrial matrix enzyme that plays a central role in extrahepatic ketone body catabolism by catalyzing the reversible transfer of coenzyme A (CoA) from succinyl-CoA to acetoacetate.
Crotonyl-CoA reductase (EC 1.3.1.86, butyryl-CoA dehydrogenase, butyryl dehydrogenase, unsaturated acyl-CoA reductase, ethylene reductase, enoyl-coenzyme A reductase, unsaturated acyl coenzyme A reductase, butyryl coenzyme A dehydrogenase, short-chain acyl CoA dehydrogenase, short-chain acyl-coenzyme A dehydrogenase, 3-hydroxyacyl CoA reductase, butanoyl-CoA:(acceptor) 2,3-oxidoreductase, CCR) is an enzyme with systematic name butanoyl-CoA:NADP+ 2,3-oxidoreductase. This enzyme catalyses the following chemical reaction
Short-chain acyl-CoA dehydrogenase is an enzyme with systematic name short-chain acyl-CoA:electron-transfer flavoprotein 2,3-oxidoreductase. This enzyme catalyses the following chemical reaction
Coenzyme A transferases (CoA-transferases) are transferase enzymes that catalyze the transfer of a coenzyme A group from an acyl-CoA donor to a carboxylic acid acceptor. Among other roles, they are responsible for transfer of CoA groups during fermentation and metabolism of ketone bodies. These enzymes are found in all three domains of life.
