ITC titration curves and relative heats of binding for cGMP binding to Bd1971ΔEAL. Successive injections of 6 µl of cNMP (0.5 - 1.6 mM) were made into 1.4 ml of apo-Bd1971ΔEAL (50 - 150 µM) and heat changes measured. The top panels show the ITC titrations and the bottom panels show the binding isotherm associated with each ITC experiment. 