A protein undergoes reversible thermal denaturation from its initial state N to denatured state D according to N D. At 60^° C, the concentrations of…

A protein undergoes reversible thermal denaturation from its initial state $\displaystyle \mathbf{N}$ to denatured state $\displaystyle \mathbf{D}$ according to $\displaystyle \mathbf{N} \rightleftharpoons \mathbf{D}$. At $\displaystyle 60^{\circ} \mathrm{C}$, the concentrations of both $\displaystyle \mathbf{N}$ and $\displaystyle \mathbf{D}$ are equal at equilibrium, and the standard enthalpy change of denaturation is $\displaystyle 666 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The standard entropy change ( $\displaystyle \Delta \mathrm{S}^{\circ}$ in $\displaystyle \mathrm{kJ} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ ) of the protein upon denaturation at $\displaystyle 60$ °C is closest to