Question

Consider the denaturation equilibrium between native Ribonuclease A and unfolded protein. Ribonuclease A is a 124 amino acid protein with four disulfide bridges. To test the importance of one of the disulfide bridges in protein stability, residues Cys58 and Cys110 were mutated into Ala. The protein denaturation parameters for Ribonuclease A wild-type and mutant are shown below. All values are in kJ/mol.

wt: ΔH: 297.2
TΔS: 254.6
ΔG: 42.4
mutant: ΔH: 184
TΔS: 183.2
ΔG: 0.8
Mark the following statement as True or False: Denaturation is spontaneous for both enzymes.
A. True
B. False

Answer 1

False

Step-by-step explanation:

We know from thermodynamics that;

When ∆G is positive the process is not spontaneous

When ∆G is negative the process is spontaneous

When ∆G is zero, the system has attained equilibrium.

In both cases, ∆G is positive hence the denaturation of both enzymes is not spontaneous, hence the answer above.