Ligand-receptor interaction. Klotz-Hunston problem for two classes of binding sites and its solution.

The problem of the affinity and quantity determination of two classes of binding sites for ligand-receptor interaction using either Scatchard or Klotz plots was considered. Klotz and Hunston previously solved this problem only for the case of a representation of experimental data using the Scatchard plot. Since their publication, it was the common view that only the use of the Scatchard plot allows solving this problem. However, in some cases, using the Klotz plot is more convenient for a representation of experimental data concerning ligand-receptor interaction, though usually, this plot was used only for the evaluation of receptor affinity with one class of binding sites. In the present paper, it was demonstrated that Klotz plot also could be used for the evaluation affinity and quantity of two classes of binding sites.