<p>(A) Activity of purified FPS1S (open symbols) and FPS2 (closed symbols) was measured after incubation at either 37°C (squares) or 45°C (circles) for the indicated time periods. (B) FPS activity in 16,000 <i>g</i> protein extracts from <i>fps1-1</i> (FPS2 activity, closed circles) and <i>fps2-1</i> (FPS1 activity, open circles) mutants was determined after incubation at 45°C for the indicated times. In both cases enzyme activities are expressed relative to the FPS activity values at time 0 min and the mean values and SE were calculated from three independent experiments. (C) Differential scanning fluorimetry (DSF) results plotted as change in fluorescence emission intensity (normalized to unity at its maximum) with increasing temperature (20–80°C). The FPS1S and FPS2 curves correspond to 6 µM enzyme.</p
