Methylcrotonyl-CoA

Overview of Methylcrotonyl-CoA

Methylcrotonyl-CoA

Methylcrotonyl-CoA is an intermediate in the leucine degradation pathway. It is involved in the metabolism of branched-chain amino acids.

Function

Methylcrotonyl-CoA is converted to 3-methylglutaconyl-CoA by the enzyme methylcrotonyl-CoA carboxylase (MCC). This reaction requires biotin as a cofactor and is an essential step in the catabolism of leucine.

Clinical significance

Deficiency in methylcrotonyl-CoA carboxylase activity can lead to a metabolic disorder known as 3-Methylcrotonyl-CoA carboxylase deficiency. This condition is characterized by the accumulation of toxic metabolites, which can cause symptoms such as hypotonia, developmental delay, and metabolic acidosis.

Pathway

The leucine degradation pathway involves several steps:

• Leucine is first transaminated to α-ketoisocaproate.
• α-Ketoisocaproate is then oxidatively decarboxylated to form isovaleryl-CoA.
• Isovaleryl-CoA is converted to methylcrotonyl-CoA.
• Methylcrotonyl-CoA is carboxylated to form 3-methylglutaconyl-CoA.
• Further steps lead to the production of acetyl-CoA and acetoacetate, which enter the citric acid cycle and ketogenesis, respectively.

See also

• Leucine metabolism
• Branched-chain amino acid metabolism
• Biotin-dependent carboxylases

External links

• Methylcrotonyl-CoA on WikiMD

• 
  Methylcrotonyl coenzyme A