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. 1995 Oct;4(10):2138–2148. doi: 10.1002/pro.5560041020

Denaturant m values and heat capacity changes: relation to changes in accessible surface areas of protein unfolding.

J K Myers 1, C N Pace 1, J M Scholtz 1
PMCID: PMC2142997  PMID: 8535251

Abstract

Denaturant m values, the dependence of the free energy of unfolding on denaturant concentration, have been collected for a large set of proteins. The m value correlates very strongly with the amount of protein surface exposed to solvent upon unfolding, with linear correlation coefficients of R = 0.84 for urea and R = 0.87 for guanidine hydrochloride. These correlations improve to R = 0.90 when the effect of disulfide bonds on the accessible area of the unfolded protein is included. A similar dependence on accessible surface area has been found previously for the heat capacity change (delta Cp), which is confirmed here for our set of proteins. Denaturant m values and heat capacity changes also correlate well with each other. For proteins that undergo a simple two-state unfolding mechanism, the amount of surface exposed to solvent upon unfolding is a main structural determinant for both m values and delta Cp.

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Selected References

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