Branched-chain amino acid (BCAA) catabolism is defined by a shared metabolic pathway for transamination, oxidative decarboxylation, and dehydrogenation followed by divergent routes that determine glucogenic or ketogenic fate. The theoretical classification relies on the enzymatic regulation of alpha-ketoacid derivatives: Valine yields succinyl-CoA (glucogenic), Leucine yields acetyl-CoA/acetoacetate (ketogenic), and Isoleucine produces intermediates for both pathways due to its dual metabolic routing. This mechanism establishes BCAA catabolism as a critical alternative fuel supply system under starvation conditions, governed by specific coenzyme dependencies such as biotin-dependent carboxylation and thiamine-dependent decarboxylation within the context of human biochemistry.
Branched-chain amino acid (BCAA) catabolism is defined by a shared metabolic pathway for transamination, oxidative decarboxylation, and dehydrogenation followed by divergent routes that determine glu…