Application of Photosensitive Immobilized α-Chymotrypsin to Synthetic Reaction

Abstract

Hydrolytic enzymes can be used to catalyze the synthesis of the compounds that they normally hydrolyze. Substances which undergo reversible color formation under light irradiation are called photochromic compounds. As previously reported, photo-synsitive immobilized enzymes were prepared by entrapping enzymes in a collagen membrane modified with a spiropyran compound (1, 2, 3). Activities of enzymes immobilized in spiropyran-collagen membranes were changed by irradiation with light. Photocontrol of activities resulted from remarkable changes in the micro-environmental characteristics around the enzymes. The polarity of spiropyran drastically chages with light irradiation. Colorless spiropyran derivatives under visible light (apolar) are converted to the colored form (polar) when they are placed in the dark. α-Chymotrypsin catalyzes the hydrolysis and synthesis of N-acetyl-L-tyrosine ethyl ester (ATEE). Therefore, photocontrol of the esterification of amino acids can be expected by using α-chymotrypsin immobilized in spiropyran membrane.