A high-resolution probe of protein folding

L.B. Sagle, J. Zimmermann, P.E. Dawson, F.E. Romesberg, J. Am. Chem. Soc. (Comm.) (2004) 126:3384-3385.
pubpic2004sagleTo generate residue-specific information on the equilibrium folding of cyt c, we have semisynthesized the protein with specifically deuterated residues. Plotted as a function of added guanidine hydrochloride denaturant, the absorption intensities of the protein C-D bonds reveal that cyt c undergoes a conformational change at the protein-based heme ligand, Met80, which is then followed by a more global unfolding at 2.3 M GdnHCL.