Enzyme immobilization utilizing a porous ceramics support for chiral synthesis

A novel porous ceramics support, named "Toyonite," for the immobilization of enzymes was prepared from the minerals of kaolinite under acidic conditions. Modification of the porous surface of Toyonite with two different organic coating agents gave Toyonite 200-M (TN-M), and Toyonite 200-A (TN-A), possessing methacryloyloxy and amino groups on the respective surfaces. Compared with other solid supports, TN-M and TN-A supports exhibited high selectivity for lipase PS (Pseudomonas cepacia, Amano) and glucoamylase (Gluczyme AF 6, Amano) proteins, respectively. The activities of both the transesterification of rac-1 with TN-M PS lipase and the hydrolysis of starch with TN-A glucoamylase were greater than those of similar reactions with these two enzymes immobilized on other solid supports. Further, TN-M PS lipase showed higher reactivity toward synthetic substrates, including aromatic and aliphatic secondary alcohols, than the free enzyme powder.