REAL-TIME NMR-STUDIES ON FOLDING OF MUTANTS OF BARNASE AND CHYMOTRYPSIN INHIBITOR-2

The folding and unfolding of proteins is generally assumed to be so co -operative that the overall process map be followed by a single probe, such as tryptophan fluorescence, Folding kinetics of three mutants of barnase and chymotrypsin inhibitor 2 (CI2) were studied by real-time NMR. Rate constants for changes in individual residues during the unfo lding or refolding of the mutants studied by real-time NMR are all wit hin experimental error of the overall process of folding/unfolding mea sured by stopped-flow measurements of tryptophan fluorescence, Folding of these mutants is thus highly cooperative, Changes in the tryptopha n fluorescence give accurate measurements of the protein folding proce ss. (C) 1998 Federation of European Biochemical Societies.