Stabilization–immobilization of carboxypeptidase A to aldehyde–agarose gels: A practical example in the hydrolysis of casein

A procedure of covalent multipoint attachment to modified 10 BCL agarose gels has been performed for stabilization–immobilization of carboxypeptidase A (CPA). All the enzyme offered to the support was immobilized, yielding an intrinsic activity of 55% as compared to the soluble enzyme. The multipoint derivative of CPA is more than 1000 times more stable than the soluble enzyme in absence of autolysis phenomena, as shown by thermal inactivation of the soluble and immobilized enzymes. In order to test the activity of this new immobilized derivative, it was used for hydrolysis of casein previously treated with chymotrypsin. Results show specific release of amino acids depending on the time of action of CPA. This immobilization–stabilization might play a very important role to allow the use of expensive enzymes in specific applications where time, temperature or the use of chemical reagents are limiting factors.