Question

Proteins can be unfolded, N → D, by increasing the temperature. In such an experiment, the fraction of a Native (N) protein was observed to be 88.6% at 335 K and 5.1% at 360 K. Find the stability of the protein (ΔG nod) at 310 K and the melting temperature Tm. In an attempt to stabilize the folded protein, a hydrogen bond is introduced into the Native structure such that ΔH nod = 225 kJ/mol and ΔS nod = 700 J/mol/K. In what way did they succeed in their goal, and in what way did they fail?

Answer 1

225k/ / mol-310K x700J / mol. K = 225kJ / mol-217.0k/ / mol -8.0kJ/mol AGod is positive so the process is non-spontaneous To succeed in their goal AG should be negative To get negative value for AG they have to increase the temperature Hence by increasing temperature they succeed in their goal