Properties of pectinesterase immobilized on glycophase-coated controlled-pore glass

Pectinesterase was immobilized on a porous glass support, which surface was covered with glyceryl residues. The parameters of the immobilization were characterized with respect to the coupling method used as well as the support pore size. Chemical modification level resulted an important parameter in determining the activity of the immobilized derivative. Attachment of the enzyme through thiol groups gave the best results, whereas a nominal pore size of 20 nm seemed to be the most suitable for the demethoxylating activity of the enzyme on citrus pectin. Optimum conditions for activity as well as the inhibition constant for polygalacturonic acid did not change on immobilization, as the Michaelis constant did. Fluorescence spectra revealed a partial unfolding of the enzyme tertiary structure when immobilized.