[UV-Modification of Free and Immobilized Trypsin].

We investigated the mechanism of UV-radiation influence on trypsin in free and immobilized (on chitosan) states. The catalytic activity of free enzyme under the action of UV-light is subjected to changes to a greater extent than that of the immobilized one. We assume that the photoprotection effect of chitosan is caused for the following reasons: firstly, through interactaction with trypsin molecules chitosan forms a more photoresistant complex as compared to the native protein; secondly, chitosan probably binds the active photopro- ducts of a free radical nature, thus preventing oxidation (destruction) of several amino acids of the enzyme under its UV-radiation.