Effect of ATP or ADP concentrations on the rates of mtMDH reactivation. The apparent rates of GroEL-mediated reactivation of mtMDH (4 μM GroEL, 0.3 μM mtMDH) was measured as in Fig. 1, in the presence of increasing concentrations of ATP (a) or ADP (b), without GroES (0 S), with limiting GroES (0.5 S; 2 μM), or with saturating amounts of GroES (3 S; 12 μM).