Figure 3

Lysine catabolism in monogastric animals. Lysine is catabolized via the saccharopine pathway and the pipecolate pathway. The enzymes involved include: (1) Lysine α-ketoglutarate reductase; (2) saccharopine dehydrogenase; (3) lysine oxidase; (4) spontaneous; (5) peperideine-2-carboxylic acid reductase; (6) pipecolate oxidase; (7) spontaneous; (8) enzymes including aminoadipate semialdehyde dehydrogenase, aminoadipate aminotransferase, α-ketoacid dehydrogenase, glutaryl-CoA dehydrogenase, glutaconyl-CoA decarboxylase, enol-CoA hydratase, and β-hydroxyacyl-CoA dehydrogenase for seven steps; (9) thiolase; (10) enzymes of the TCA cycle. Adapted from Wu (2013a).