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 may 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 unfolding or refolding of the mutants studied by real-time NMR are all within experimental error of the overall process of folding/unfolding measured by stopped-flow measurements of tryptophan fluorescence. Folding of these mutants is thus highly co-operative. Changes in the tryptophan fluorescence give accurate measurements of the protein folding process.
Killick
T R
TR
Cambridge Centre for Protein Engineering, Department of Chemistry, University of Cambridge, UK.
Freund
S M
SM
Fersht
A R
AR
D001426:Bacterial Proteins; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D010940:Plant Proteins; D017510:Protein Folding; D012260:Ribonucleases / Q000737:chemistry* / Q000235:genetics; D013997:Time Factors
D001426:Bacterial Proteins; D010455:Peptides; D010940:Plant Proteins; C093336:chymotrypsin inhibitor 2; D012260:Ribonucleases; C019760:Bacillus amyloliquefaciens ribonuclease