4.1.1.11 L-aspartate = beta-alanine + CO2 - - 4.1.1.11 L-aspartate = beta-alanine + CO2 detailed catalytic mechanism 650836 4.1.1.11 L-aspartate = beta-alanine + CO2 in the apo structure, N-terminal Ser25 of alpha chain is converted to pyruvoyl group. Substrate analogue isoasparagine becomes covalently attached to the pyruvoyl group forming the Schiff base intermediate prior to decarboxylation 666021