A small globular protein has an unfolding enthalpy and melting temperature

PHYSICS · Multi-part · Fermi University Physics · Thermal, Statistical & Complex Systems · Biophysics & Medical Physics · Macromolecules, membranes and cell architecture

Forces, Machines and Signals, Ch Free energy at work: states, weights and entropic forces

Problem

A small globular protein has an unfolding enthalpy ΔHm=350 kJ mol−1\Delta H_m = 350\,\mathrm{kJ\,mol^{-1}} and melting temperature Tm=328 KT_m = 328\,\mathrm{K}. Treating it as a two-state folder with ΔGunf(T)≈ΔHm(1−T/Tm)\Delta G_{\rm unf}(T) \approx \Delta H_m\left(1-T/T_m\right) near TmT_m, ((a)) find ΔGunf\Delta G_{\rm unf} at 298 K298\,\mathrm{K}, in kJ mol−1\mathrm{kJ\,mol^{-1}} and in kBTk_BT; ((b)) find the fraction of molecules unfolded at 298 K298\,\mathrm{K}; ((c)) find the width of the transition, 4RTm2/ΔHm4RT_m^2/\Delta H_m.

Browse the problem library