Chapter 6, Problem 24P

Cartoon renderings of the proteins Top 7 and adaH2 are shown below. Both are soluble, densely packed proteins of roughly 96 residues, and each has a topology of 2 a helices packed onto a 5-stranded ß sheet.

The accompanying table lists some information about the amino acid composition and values of ΔS⁰ for the folding of these proteins (i.e. for Unfolded →Folded) at 25⁰C. Based on the information in the table, which protein do you predict buries the greater hydrophobic surface area upon folding? Assume 2-state folding (i.e., no intermediates), and that the Unfolded state for both proteins is 100% solvent-exposed. Explain your answer in terms of expected contributions from ΔS⁰_peptide and ΔS⁰_solvent.