In enzymology, an aspartate 4-decarboxylase is an enzyme that catalyzes the chemical reaction Hence, this enzyme has one substrate, L-aspartate, and two products, L-alanine and CO2. This reaction is the basis of the industrial synthesis of L-alanine. This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is L-aspartate 4-carboxy-lyase (L-alanine-forming). Other names in common use include desulfinase, aminomalonic decarboxylase, aspartate beta-decarboxylase, aspartate omega-decarboxylase, aspartic omega-decarboxylase, aspartic beta-decarboxylase, L-aspartate beta-decarboxylase, cysteine sulfinic desulfinase, L-cysteine sulfinate acid desulfinase, and L-aspartate 4-carboxy-lyase. This enzyme participates in alanine and aspartate metabolism and cysteine metabolism. It employs one cofactor, pyridoxal phosphate.