Figure 4. Hsp70 supports Hsp104 in disaggregation, compensating the effect of ADP.
(A) The opposing effects of ADP and Hsp70 on Hsp104 affinity towards aggregates. Disaggregation of heat-aggregated GFP present at different concentrations by Hsp104 D484K variant (0.06 μM) was assessed at 10 mM ATP, with or without ADP (1 mM), in the presence or absence of Ssa1 (2 μM) and Ydj1 (0.5 μM), as indicated in the legend. The initial rate of recovery of GFP fluorescence was plotted against GFP concentration. Data are the means of three measurements (± SD). Dashed lines represent Michaelis-Menten curves fitted to each set of experimental data using least squares fitting with the GraphPrism software. a. u. – arbitrary units. (B) Apparent KM values calculated for each experiment described in (A). Values are average of three experiments (± SD).