GdnHCl-denatured protein

By addition of a suitable amount of a chemical denaturant (in this case guani-dinium hydrochloride GdnFFCl) the protein can be made to folly unfold or can be poised at the mid-point of a transition determined by an ensemble equilibrium denaturation experiment. Rhoades recorded the histograms of FRET efficiency for the protein under native, denaturing and mid-point conditions (this was determined to be 0.55 M GdnFlCl for adenylate kinase under these conditions). These data indicate a FRET efficiency of 0.8 in the folded state and 0.14 in the folly denatured state (2 M GdnHCl). At a GdnHCl concentration of 0.4 M the presence of two sub-populations was detected. At this concentration of denaturant the protein will spend an almost equal amount of time in the folded and unfolded... 

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