Protein Structure and Folding Thermodynamics

A protein has a melting temperature (Tm) of 65°C. The enthalpy of unfolding (ΔH°unfold) at Tm is 500 kJ/mol. (a) Calculate the entropy of unfolding (ΔS°unfold) at Tm. (b) Calculate ΔG°unfold at 25°C, assuming ΔH° and ΔS° are temperature-independent. (c) Explain the hydrophobic effect's contribution to protein folding thermodynamics. (d) Why do proteins denature at both high and low temperatures? (e) How would a mutation that replaces a buried leucine with alanine affect the protein's stability?