[Action of ultraviolet radiation on chymotrypsin solutions]

The article deals with the influence of UV-radiation (gamma-254 nm) on the chymotrypsin solutions in the atmosphere of O2, Ar and CO2 at 5 degrees C and 40 degrees C as well as with the processes of aftereffect. Inactivation of chymotrypsin due to irradiation was accompanied by formation of SH-groups, high and low molecular weight compounds with low activity and inactive products of photolysis. An increase in temperature led to a greater chymotrypsin inactivation and increase in the number of SH-groups and aggregates, and to a greater photolysis of the enzyme molecules. The irradiation in the atmosphere of O2 and Ar revealed no differences in the course of chymotrypsin inactivation. Nevertheless, it was found that in Ar the yield of high-molecular compounds, their activity and the number of SH-groups exceeded those in O2. In the presence of O2 the formation of active products of low molecular weight increased. Irradiation in the atmosphere of CO2 contributed to the aggregation of the enzyme molecules and increased inactivation of all products as compared with Ar and O2. It is shown that after irradiation there occurs the further inactivation of the enzyme which is accompanied by formation of new fractions. A possible mechanism of chymotrypsin inactivation is discussed.