Question

The denaturation of proteins can be described by the equilibrium

F⇌U

where F and U represent the folded and unfolded proteins, respectively.

For lysozyme, Δ_uH^0′_298K= 335kJ/mol and Δ_uS^0′_298K= 980J/K.mol. The subscript 'u' refers to 'unfolding'.

A) Calculate the equilibrium constant for the equilibrium F⇌Uat 298K

B) Suppose you dissolve a certain amount of lysozyme in aqueous buffer at 298K. What fraction of the lysozyme protein molecules will be unfolded once equilibrium is reached?

The fraction of unfolded lysozyme is the concentration of unfolded lysozyme divided by the total concentration of lysozyme (folded + unfolded) in solution. Note that you do not need knowledge of the total amount of protein to answer this question.

C) Assume Δ_uH^0′_298K and Δ_uS^0′_298K can be considered constant in the range 10°C-80°C. Calculate K' at 50°C.

Answer 1