Question

BIOCHEMISTRY: What are the three enzyme subunits in the PDH complex and the reactions they catalyze?

Answer 1

Three enzymes involved in PDH complex (often called as PDC: Pyruvate dehydrogenase complex):

1) Pyruvate dehydrogenase:

Reaction catalyzed:

Pyruvate + [dihydrolipoyllysine-residue acetyltransferase] lipoyllysine [dihydrolipoyllysine-residue acetyltransferase] S-acetyldihydrolipoyllysine + CO(2)

2) Dihydrolipoyl transacetylase:

Reaction catalyzed:

Acetyl-CoA + enzyme N(6)-(dihydrolipoyl)lysine CoA + enzyme N(6)-(S-acetyldihydrolipoyl)lysine

3) Dihydrolipoyl dehydrogenase

Reaction catalyzed:

Protein N(6)-(dihydrolipoyl)lysine + NAD(+) protein N(6)-(lipoyl)lysine + NADH