Fig. 7.

Thermal stability of total cellular proteins from the parental and the mutant strains. Cells from an exponentially grown culture of the parental strain or ΔaKMT were harvested, resuspended in 50 mm sodium phosphate buffer, pH 7.0, and sonicated. A, The clarified cell-free extracts were heated from 50 to 95 °C at a rate of 0.2 °C/min, and the increase in absorbance at 600 nm was recorded on a Shimadzu UV-2550 spectrophotometer. B, The cell-free extracts were incubated at 65, 75, 85, or 95 °C for 15, 30, 60, and 120 min. Protein aggregation was monitored by 90° light scattering at 488 nm on a Shimadzu RF5301PC spectrofluorimeter.