Theory of large-amplitude conformational fluctuations in native globular proteins. Independent fluctuating site model.
A theory is developed about large-amplitude conformational fluctuations in globular proteins in their native or predenaturational state. A model is introduced, an independent fluctuating site model, in which we assume that there is more than one independent fluctuating site, each one localized in some part of a protein molecule. Without assuming any further details for each fluctuating site, the entropy S versus enthalpy H curve of this model is shown to be convex. From this fact the predenaturational excess heat capacity can be derived, as observed in recent experimental studies of a few systems of a protein in solution.
D008433:Mathematics; D008956:Models, Chemical; D011487:Protein Conformation