Which of the following enzymes is involved in the degradation of branched-chain amino acids?

A Branched-chain ketoacid dehydrogenase complex ✓
B Phenylalanine hydroxylase
C Tyrosinase
D Homogentisate 1,2-dioxygenase

Explanation

The branched-chain ketoacid dehydrogenase complex is a mitochondrial enzyme complex that catalyzes the degradation of branched-chain amino acids (leucine, isoleucine, and valine). Deficiency of this enzyme complex leads to maple syrup urine disease.

Source

Scriver's The Metabolic and Molecular Bases of Inherited Disease
Metabolic and Nutritional Disorders Biochemistry Amino Acid Metabolism Hard MEDICAL Confidence: high