Α-Ketobutyric acid

Α-Ketobutyric acid (also known as 2-oxobutanoic acid or alpha-ketobutyric acid) is a ketone body and an intermediate in the metabolism of amino acids. It is a four-carbon organic compound and a keto acid.

Structure and properties

Α-Ketobutyric acid is a carboxylic acid with a ketone functional group. It has the chemical formula C4H6O3. The molecule consists of a butyric acid backbone with a keto group at the second carbon atom, hence the prefix 'α' in its name. The compound is a colorless liquid and has a pungent odor.

Biological role

In biological systems, α-ketobutyric acid is produced from threonine through the process of threonine dehydrogenase. It can also be produced from methionine via a transamination reaction involving L-methionine and pyruvate.

Α-Ketobutyric acid is an important intermediate in the citric acid cycle, where it is converted to succinyl-CoA by the enzyme alpha-ketobutyrate dehydrogenase. Succinyl-CoA then enters the citric acid cycle, contributing to the production of adenosine triphosphate (ATP), the main energy currency of the cell.

Clinical significance

Abnormal levels of α-ketobutyric acid in the body can be indicative of certain medical conditions. For instance, elevated levels can be a sign of maple syrup urine disease, a rare inherited metabolic disorder.

See also

• Ketone bodies
• Keto acid
• Metabolism
• Citric acid cycle