<p>(A) Stimulation of DnaK ATPase activity under steady state conditions. DnaK(1 µM) and GrpE (0.5 µM) in the absence or in the presence of DnaJ, Rki or Rki(H38Q) at the indicated concentrations. The percentage hydrolyzed ATP/min is plotted as a function of the final DnaJ concentration used in the reaction mix. (B) Refolding chemically-denatured firefly luciferase (125 nM) by DnaK (500 nM) and GrpE (125 nM) in the presence of 125 nM of either DnaJ, Rki or Rki(H38Q) as indicated. The values of luciferase refolding were normalized to the maximal value obtained with that of wild type DnaJ. (C) Luciferase aggregation protection assay. A representative plot of a luciferase aggregation protection assay is shown with chemically-denatured luciferase (1 µM) alone (no JDP), or in the presence of DnaJ (1 µM), Rki (1 µM or 4 µM). Optical densities were measured at 320 nm and the percentage values were normalized to the luciferase aggregation obtained in the absence of added chaperones.</p
