Protein A interacts with biomolecule B and forms a complex AB, with a dissociation constant KD = 1 µM at 25 °C, (for dis
Posted: Thu Jul 07, 2022 2:01 pm
Protein A interacts with biomolecule B and forms a complex AB, with a dissociation constant KD = 1 µM at 25 °C, (for dissociation, AB = A + B, KD=[A]/[AB]). The interface contains a phenylalanine residue. A biochemist mutated the phenylalanine of protein A to a tyrosine (A'), which introduced a hydrogen bond between the hydroxyl group of the tyrosine with B without affecting any other interactions. The formation of the hydrogen bond releases a heat at 11.4 kJ/mol. What is the KD of the complex of the mutant A' with B? Hint: Gas constant R = 8.3145 J/K/mol, Euler's number e = 2.7183, In(A) - In(B) = In(A/B).