A method to estimate binding constants at variable protein concentrations.

The association constants of the binding of chlorpromazine and imipramine to serum albumin at low saturation of the protein were determined by a new experimental approach with the protein concentration rather than the ligand concentration being varied. This approach is suitable for estimating binding constants in systems with one class of binding sites. In addition, the method is proposed to complement conventional binding studies of systems with two classes of binding constant with higher accuracy.