Methylmalonic acid

Methylmalonic acid (MMA) is a dicarboxylic acid that is a vital intermediate in the metabolism of fat and protein. It is a substance that is produced when proteins, specifically those containing the amino acid methionine, are broken down in the body.

Chemistry

Methylmalonic acid is a chiral compound with two enantiomers, (R)- and (S)-methylmalonic acid. It is a colorless, crystalline solid that is soluble in water. The chemical formula for methylmalonic acid is C4H6O4.

Biosynthesis

Methylmalonic acid is produced in the body during the metabolism of certain amino acids and odd-chain fatty acids. The process begins with the conversion of these substances into propionyl-CoA, which is then converted into methylmalonyl-CoA by the enzyme propionyl-CoA carboxylase. Methylmalonyl-CoA is then converted into succinyl-CoA, a key intermediate in the citric acid cycle, by the enzyme methylmalonyl-CoA mutase.

Clinical significance

Elevated levels of methylmalonic acid in the blood, a condition known as methylmalonic acidemia, can be a sign of several different health problems, including vitamin B12 deficiency, kidney disease, and certain genetic disorders. Methylmalonic acidemia is a serious condition that can lead to developmental delays, failure to thrive, and other health problems if not treated promptly.

See also

• Propionic acidemia
• Methylmalonic aciduria
• Methylmalonyl-CoA mutase deficiency