Synthesis and properties of an insoluble chitosan resin modified by azamacrocycle copper(II) complex for protein hydrolysis

摘要

We reported the synthesis process and the proteolytic ability of a novel crosslinked chitosan resin modified by azamacrocycle copper complex (CMCR). Characterization of CMCR showed that the Cu(II)Cyclen complex had successfully bound to the resin matrix covalently. Its proteolytic activity toward peptide bonds was evaluated by investigating the hydrolysis of bovine serum albumin in heterogeneous media. The maximum-observed pseudo-first-order rate constant (k_(obs)) was achieved under 60°C, pH 6.0, where protein was hydrolyzed into smaller peptides and amino acids confirmed by SDS-PAGE and ninhydrin reaction. The results indicated that the hydrolyzing efficiency delivered by CMCR was 4 × 10~5 times higher than that of spontaneous hydrolysis. CMCR also featured a desirable stability for chelating Cu~(2+) ions, which paved the way for its feasible recovery process and good reusability.