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Protease immobilization onto porous chitosan beads
Author(s) -
Hayashi Toshio,
Ikada Yoshito
Publication year - 1991
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1991.070420110
Subject(s) - proteases , chemistry , hydrolysis , papain , protease , immobilized enzyme , chitosan , casein , substrate (aquarium) , michaelis–menten kinetics , chromatography , enzyme , enzyme assay , organic chemistry , oceanography , geology
Water‐insoluble proteases were prepared by immobilizing papain, ficin, and bromelain onto the surface of porous chitosan beads with any length of spacer by covalently fixation. The activity of the immobilized proteases was found to be still high toward small ester substrate, N‐ benzyl‐ L ‐arginine ethyl ester (BAEE), but rather low toward casein, a high‐molecular‐weight substrate. The relative activity of the immobilized proteases with spacer gave an almost constant value for the substrate hydrolysis within the surface concentration region studied. The values of the Michaelis constant K m and the maximum reaction velocity V m for free and immobilized proteases on the porous chitosan beads are estimated. The apparent K m values were larger for immobilized proteases than for the free ones, while V m values were smaller for the immobilized proteases. The pH, thermal, and storage stability of the immobilized proteases were higher than those of the free ones. The initial enzymatic activity of the immobilized protease maintained almost unchanged without any elimination and inactivation of proteases, when the batch enzyme reaction was performed repeatedly, indicating the excellent durability.