My interest in these compounds is rooted in their link to adrenal hormone regulation and cholesterol blood lipids. Here’s some general information and background:
Coenzyme A (CoA, CoASH, or HSCoA) 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, such as acetyl-CoA) as a substrate. In humans, CoA biosynthesis requires cysteine, pantothenate, andadenosine triphosphate (ATP). – Wikipedia
Since coenzyme A is, in chemical terms, a thiol, it can react with carboxylic acids to form thioesters, thus functioning as an acyl group carrier. It assists in transferring fatty acids from the cytoplasm to mitochondria. A molecule of coenzyme A carrying an acetyl group is also referred to as acetyl-CoA. When it is not attached to an acyl group, it is usually referred to as ‘CoASH’ or ‘HSCoA’.
Coenzyme A is also the source of the phosphopantetheine group that is added as a prosthetic group to proteins such as acyl carrier protein and formyltetrahydrofolate dehydrogenase. – Wikipedia
Acetyl coenzyme A or acetyl-CoA is an important molecule in metabolism, used in many biochemical reactions. Its main function is to convey the carbon atoms within the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Structure of coenzyme A (CoASH or CoA) consists of a β-mercaptoethylamine group linked to the vitamin pantothenic acid through an amide linkage. The acetyl group of acetyl-CoA is linked by a “high energy” thioester to the sulfhydryl portion of the β-mercaptoethylamine. It is this thioester bond that makes acetyl-CoA one of the “high energy” compounds. Hydrolysis of the thioester bond is highly exergonic (-31.5 kJ). Acetyl-CoA is produced during breakdown of carbohydrates through glycolysis as well as fatty acid oxidation and enters the citric acid cycle.
Acetyl-CoA is also an important component in the biogenic synthesis of the neurotransmitter acetylcholine. Choline, in combination with acetyl-CoA, is catalyzed by the enzyme choline acetyltransferase to produce acetylcholine and a Coenzyme A byproduct. – Wikipedia