Refolding of denatured MDH by GroEL and Pf-cpn20.

Urea-denatured malate dehydrogenase was refolded by GroEL with the help of Pf-cpn20, using At-cpn20 and GroES as control co-chaperonins. A) Refolding yields as a function of the co-chaperonin/GroEL protomer ratio. The refolding reaction was carried out for 30 minutes with 10 µM GroEL and increasing co-chaperonin concentration (0.16 to 20 µM), as described in Materials and Methods. Refolding is expressed relative to the highest yield obtained with GroES. B) Refolding yield as a function of time carried out with 10 µM GroEL and a sub-saturating co-chaperonin concentration (2 µM) Values represent the average of 3 independent experiments +/− standard deviation.