Evidence for an unfolding and refolding pathway in cytochrome c.
It has been suggested that three partially unfolded forms detected in a native state hydrogen exchange study of oxidized cytochrome c may represent sequential intermediates in an unfolding-refolding pathway. To better define the structure of each intermediate a 'stability labeling' method was used in which the stability of a given segment against unfolding was changed. The condition--folded or unfolded--of the stability-labeled segment in each intermediate could then be determined. The structures found are discrete and native-like and are just those necessary for a sequential pathway.
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Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia 19104, USA.
Mayne
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Englander
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D000818:Animals; D001665:Binding Sites; D003574:Cytochrome c Group / Q000737:chemistry*; D006418:Heme / Q000737:chemistry; D006736:Horses; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008715:Methionine / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D013816:Thermodynamics
D003574:Cytochrome c Group; D006418:Heme; D006859:Hydrogen; D008715:Methionine