Effect of various chaperones on rhodanese folding. Denatured rhodanese in 6 M guanidine-HCl was rapidly diluted (>200 fold) into buffer B containing the indicated chaperones. For all experiments, the final rhodanese concentration was 100 nM. The final yields of rhodanese activities are reported as the fraction relative to that produced in the presence of GroEL, GroES, and ATP at 25°C, which represents ≈70% of the input material. (A) Rhodanese folding experiments were carried out at 25°C in the presence of the following concentrations of chaperones: 10 μM GroEL and 15 μM GroES protomers (EL/ES/ATP), 10 μM GroEL protomers (EL/ATP); 10 μM sht-GroEL191–345 (sht345); 100 μg/ml α-casein (casein); 100 μg/ml BSA; 0 μM GroEL (Spont.).ATP(5 mM) was present, where indicated. (B) Folding experiments were carried out as in B except that the temperature was 37°C.