Immobilization of Carboxypeptidase A into Modified Chitosan Matrixes by Covalent Attachment

MANZO, RICARDO M.; CERUTI, ROBERTO J.; BONAZZA, HORACIO L.; ADRIANO, WELLINGTON S.; SIHUFE, GUILLERMO A.; MAMMARELLA, ENRIQUE J.

APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY

HUMANA PRESS INC

Lugar: Oregon; Año: 2018 vol. 185 p. 1029 - 1043

0273-2289

Carboxypeptidase A (CPA) is a metalloexopeptidase that catalyzes the hydrolysis ofthe peptide bonds that are adjacent to the C-terminal end of a polypeptide chain. The enzymepreferentially cleaves over C-terminal L-amino acids with aromatic or branched side chains.This is of main importance for food industry because it can be employed for manufacturingfunctional foods from different protein sources with reduced hydrophobic amino acid contentfor patients with deficiencies in the absorption or digestion of the corresponding amino acids.In that way, strategies for effective multipoint covalent immobilization of CPA metalloenzymeon chitosan beads have been developed. The study of the ability to produce several chemicalmodifications on chitosan molecules before, during and after its coagulation to form carrierbeads lead in a protective effect of the polymer matrix. The chemical modification of chitosanthrough the use of an N-alkylation strategy produced the best derivatives. N-alkyl chitosanderivative beads with D-fructose presented values of 0.86 for immobilization yield,314.6 IU g−1 bead for initial activity of biocatalyst and were 5675.64-fold more stable thanthe free enzyme at 55 °C. Results have shown that these derivatives would present a potentialtechnological application in hydrolytic processes due to both their physical properties, such aslow swelling capacity, reduced metal chelation ability and bulk mesoporosity, and increasedoperational stability when compared with soluble enzyme.