Propionyl-CoA
From Wikipedia, the free encyclopedia
Propionyl-CoA | |
---|---|
![]() |
|
Identifiers | |
CAS number | [ | ]
PubChem | |
MeSH | |
Properties | |
Molecular formula | C24H40N7O17P3S |
Molar mass | 823.599 |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Propionyl-CoA is a coenzyme A derivative of propionic acid.
It is formed as a product of beta-oxidation of odd-chain fatty acids, which occur in meat of ruminant animals. It is also a product of metabolism of isoleucine and valine. In mammals propionyl-CoA is converted to (S)-methylmalonyl-CoA by propionyl-CoA carboxylase, a biotin-dependent enzyme also requiring bicarbonate and ATP. This product is converted to (R)-methylmalonyl-CoA by methylmalonyl-CoA racemase. (R)-Methylmalonyl-CoA is converted to succinyl-CoA by methylmalonyl-CoA mutase, an enzyme requiring cobalamin to catalyze the carbon-carbon bond migration. A defect in methylmalonyl-CoA mutase enzyme results in methylmalonic aciduria, a dangerous disorder that causes a lowering of blood pH.
In plants and insects propionyl-CoA is metabolized to acetate in a very different way, similar to beta oxidation. Not all details of this pathway have been worked out, but it appears to involve formation of acrylyl-CoA, then 3-hydroxypropionyl-CoA. This is metabolized with loss of carbon 1 of 3-hydroxypropionyl-CoA as carbon dioxide, while carbon 3 becomes carbon 1 of acetate.
[edit] Reference
Halarnkar, P.P., Blomquist, G.J. (1989) Comparative aspects of propionate metabolism. Comp. Biochem. Physiol. 92B, 227-231.