Figure 3. Calorimetric data for competition binding experiments.

ITC titration of a mixture of A3 (25 μM) pre-bound to bA3–17 (43 μM) with bA3–2 (350 μM). In these conditions, the apparent binding constant for bA3–2 decreases within the range required for ITC. Determination of the K_app is given by: K_app  = K_a ^bA3–2/(1+ K_a ^bA3–17 [bA3–17]). ΔH^bA3–17 and K_a ^bA3–17 used in the data analysis had been determined in Fig. 2–B.