Structural biology: analysis of protein-folding cooperativity.
The folding of small proteins has been assumed to be an all-or-none process that involves high cooperativity within the structure and substantial kinetic-energy barriers. Sadqi et al. claim that the small re-engineered protein Naf-BBL unfolds without significant cooperativity or kinetic hindrance, a conclusion that is based on calculation of a broad distribution of midpoint thermal-transition temperatures measured by the nuclear magnetic resonance (NMR) chemical shifts of 158 protons. We find that all of the unprocessed melting curves can be fitted to the same two-state global unfolding when uncertainties in the experimental data are taken into account. We conclude that the authors' melting data for Naf-BBL remain consistent with the all-or-none process.
Zhou
Zheng
Z
Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, NCI, NIH, Building 37, Room 6114E, Bethesda, Maryland 20892, USA. yawen@helix.nih.gov
Bai
Yawen
Y
D000494:Allosteric Regulation; D016477:Artifacts; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D012107:Research Design; D013816:Thermodynamics; D044366:Transition Temperature
D011506:Proteins