Thermostability assays and the relative specific activity of LipK107 and its variants. (A) Inactivation as a function of temperature. Residual activity was measured at 37°C after incubation of LipK107 and its variants for 30 min at various temperatures. (B) Time-course of thermal inactivation at 50°C. Results are the average of three independent experiments. (█) LipK107 WT, (•) LipK107 D113A, (▴) LipK107 D149K, (▾) LipK107 D213A, and (◆) LipK107 D253A. (C) The relative specific activity of LipK107 and its mutants. Lipase activities were determined at 37°C, and the specific activities of mutants were expressed as a percentage of the LipK107. The values shown are the means of three independent experiments.