Carboxy-lyases, also known as decarboxylases, are carbon–carbon lyases that add or remove a carboxyl group from organic compounds.These enzymes catalyze the decarboxylation of amino acids, beta-keto acids and alpha-keto acids. Carboxy-lyases, also known as decarboxylases, are carbon–carbon lyases that add or remove a carboxyl group from organic compounds.These enzymes catalyze the decarboxylation of amino acids, beta-keto acids and alpha-keto acids. Carboxy-lyases are categorized under EC number 4.1.1.Usually, they are named after the substrate whose decarboxylation they catalyze, for example Pyruvate decarboxylase catalyzes the decarboxylation of Pyruvate