Fig. 2.

Stability measurements of the DHFR_Mp part of the chimera in bulk solution. The stability of the DHFR_Mp part of the chimera was determined as a function of GuHCl concentration at different fixed concentrations of NADPH. Shown are the free energies of unfolding, in the absence of GuHCl, plotted against a function of the concentration of NADPH (S) for wild-type DHFR_Mp and the L9V, I41V, I61V, L93V, and I95V mutants. The data were fitted using Eq. 2. The y-intercepts correspond to the free energies of folding in bulk solution provided in Table 1. Error bars represent SE.