Binding studies using protection and interference

The calorimeter cell contained 80 pM protein (0.6 ml) and a solution containing 0.6 mM ligand was added in 5 pi increments. The reac- 

The upper solid line represents the measured heat capacity, lower lines show the deconvolution with solid lines for the individual melting 

150 kj mor1 and 300 kj mol-1, respectively) of both domains. The dashed line shows the heat capacity change (15 kj K- mol- ) without melting transitions. 

At the beginning of this reaction, when we assume that the concentration of product C is zero, the initial rate is proportional to the concentrations of A and B. It is often the case for biochemical reactions that the association rate constant k12 is limited by the rate at which the species A and B encounter one another in solution, and this is in the range 108—109 M-1 s-1. With rate constants of this magnitude, conventional mixing techniques can only be used when the concentrations of reactants are extremely low. 

The time resolution of this equipment is limited by the speed of mixing of the solutions, and the rate of transfer from the mixing chamber into the observation 

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