Semilogarithmic plots of the activities of CK incubated in 20 mM Tris-HCl buffer, pH 8.05, with different concentrations of glycerol at 50°C for up to 60 min. Glycerol concentrations were 0% (•), 5% (▵), 10% (*), 20% (○), and 30% (▪). Enzyme activity was determined in aliquots taken at suitable time intervals, and the final enzyme concentration was 4 μM.