[Kinetic regularities of thermal inactivation of superoxide dismutase].

An interest to the study of superoxide dismutase (SOD) is growing as it has become known that this enzyme may be used as a medical preparation and in the biochemical research. The aim of the work presented is to investigate the influence of temperature and UV radiation on the structural-functional properties of SOD. Copper- and zinc-containing SOD from bovine erythrocytes with the light of a DRT-400 lamp (dose of irradiation 1.5 x 10(3) J/m2) through an UFS-1 light filter (240-390 nm). The influence of temperature (20-85 degrees C) on the functional properties of native and UV modified SOD has been studied. The process of thermodenaturation of the enzyme proceeds at least two consecutive stages. SOD is stable within the temperature interval 20-70 degrees C. Kinetics of thermodenaturation of protein has been studied. It was established that UV light increases enzyme thermostability. Changes found in the kinetic characteristics of the UV-irradiated SOD are apparently due to its conformational rearrangements.