Two-state vs. multistate protein unfolding studied by optical melting and hydrogen exchange.
A direct conflict between the stabilization free energy parameters of cytochrome c determined by optical methods and by hydrogen exchange (HX) is quantitatively explained when the partially folded intermediates seen by HX are taken into account. The results support the previous HX measurements of intermediate populations, show how intermediates can elude the standard melting analysis, and illustrate how they confuse the analysis when they are significantly populated within the melting transition region.
Mayne
L
L
The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia 19104, USA. leland@HX2.Med.Upenn.Edu
Englander
S W
SW
D003574:Cytochrome c Group / Q000737:chemistry*; D019791:Guanidine; D006859:Hydrogen; D007700:Kinetics; D008958:Models, Molecular; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013816:Thermodynamics
D003574:Cytochrome c Group; D006859:Hydrogen; D019791:Guanidine