Question

Inkeq Page 1 > of 3 1/T (1/K) 3) For the binding of Protein X to Protein Y, where kon = 1EM's' and kom = 1E s'. a. What is the affinity of Protein X for Protein Y? b. Compute the associate rate and dissociation rates at the following concentrations of free Protein Y: kon koff [Y] = 1nM [Y] = 100 nM [Y] = 10 MM 4) For each case below, choose which one of the following biochemical techniques you would use to measure the equilibrium binding constant?

Answer 1

K_D is the measure of protein binding affinity and is given by

Kp koff kon

a.Affinity of protein X for protein Y,
15-- Kp = 15 M-1,-1

= 1E-7M

b. For [Y]=1nM=1 E^-9M, associate rate

= kon [X] [Y] = kon Y2 = 1EM-1:-1 (1E-9M)2 = 1E-13M 5-1

dissociate rate

= koff [XY] = koff [Y] = 1E--+ x 16-18 M = 15-20 M45-

for [Y]=100nM=1E^-7M,

associate rate

= kon [X] [Y] = kon [Y]° = 1EⓇM'-1*(1E-7M)' = 1E-9M5-1

dissociate rate

= kof{ [XY] = koji [72] = 1E--1 x (1E-?M? = 1E-16 Mºs-1

for [Y]=10$\mu$M=1E^-6M

associate rate

= kon Y 2 = 1EM-1:-1 (1E-6M)2 = 1E-?Ms-1

dissociate rate

= koff [Y2 = 15-25-1 x 1E-12M = 1E-14 Ms-1