Figure 3.

GroES dependency of macromolecular crowding effects. (A) Absence of transfer of rhodanese from wild-type GroEL to GroEL337/349 in a 30% Ficoll 70 solution in the presence of GroES. The separation profile of the chaperonin molecules by ion-exchange chromatography and the percentage of total [³H]rhodanese associated with either wild-type or trap-GroEL is shown before and after incubation with ATP. Retention times are given in min. (B) Chaperonin-mediated rhodanese refolding in buffer and in a 30% Ficoll 70 solution in the absence or presence of a 4-fold molar excess of GA-GroEL (trap-GroEL). Rhodanese-GroEL complexes first were preincubated for 20 min either without (reactions 1 and 2) or with (reactions 3 and 4) ATP in the absence (reactions 1 and 3) or presence (reactions 2 and 4) of trap-GroEL. Folding then was initiated by adding GroES or GroES and ATP. GroEL/GroES-mediated rhodanese refolding in buffer in the absence of trap-GroEL is set to 100%.