APPLICATION OF A CHEMOENZYMATIC GLYCOSYLATION METHOD TO ALPHA-CHYMOTRYPSIN AND CANDIDA-RUGOSA LIPASE SURFACE MODIFICATIONS

A recently developed chemoenzymatic glycosylation procedure has been s uccessfully applied on two hydrolytic enzymes, alpha-chymotrypsin and Candida rugosa lipase. First, a number of sucrose molecules have been bound to the surface lysine residues and then, lengthening of the glyc osidic chains has been carried out by the action of a levansucrase fro m Bacillus subtilis. For both steps, reaction conditions have been stu died in order to obtain a range of glycosylation degrees. The influenc e of glycoside binding on biocatalyst surface characteristics has been assessed and a progressive increase in global enzyme hydrophilic char acter with glycosylation has been observed. Besides, the study of hydr olytic activity and kinetic constants showed that the performed modifi cations brought about a certain decrease in enzyme hydrolytic activity and very slight variations in enzyme-substrate affinity.