Analysis of Two-State Folding Using Parabolic Approximation II: Temperature-Dependence

Equations that govern the temperature-dependence of the rate constants, Gibbs energies,enthalpies, entropies and heat capacities of activation for folding and unfolding of spontaneously-folding fixed two-state systems have been derived using a procedure that treats the denatured and the native conformers as being confined to harmonic Gibbs energy wells. The notion that a two-state system is physically defined only for a set temperature range is introduced. The implications of this novel treatment for protein folding are discussed.