1.1.1.346 - 38 temperature stability of isoform 2,5-diketo-D-gluconate reductase I is measured by storing the enzyme in 0.1 M Tris-HC1 buffer (pH 7.0) for 1 h. The activity of the enzyme decreases gradually with temperature from 0°C to 27°C, falls rapidly above 27°C, and is lost completely at about 38°C. The remaining activity at 27°C is about 77% of that at 0°C 440303 1.1.1.346 40 80 after approximately 10 min of deactivation, enzyme activity attains a constant value, independently of deactivation temperature (40-80°C). This value corresponds to the 30% of native activity 721898