In interactions between proteins, each hydrogen bond contributes to the free energy of binding by about -4 kJ/mole. If two proteins bind to each other through nine hydrogen bonds, six of which are eliminated when one of these proteins is mutated, how much would you expect the equilibrium constant for their binding to change as a result of the mutation? (ΔG° = -5.9 × log Kₑq)
A) Increase sixfold
B) Decrease fourfold
C) Decrease by six orders of magnitude
D) Increase 1 million-fold
E) Decrease by four orders of magnitude

Question

Quizplus · Accepted Answer

Elimination of six hydrogen bonds in the interaction increases the ΔG° value by about 24 kJ/mole, which corresponds to a 10,000-fold decrease in the binding equilibrium constant.

In Interactions Between Proteins, Each Hydrogen Bond Contributes to the Free