Estimation of receptor-ligand interactions by the use of a two-marker system in affinity capillary electrophoresis

The study of receptor-ligand interactions by affinity capillary electrophor esis (ACE) requires an accurate form of analysis. Here, we examine the use of two noninteracting standards (markers) in the analysis of binding consta nt data in ACE studies. This concept is demonstrated using two model system s: carbonic anhydrase B (CAB, EC 4.2.1.1) and arylsulfonamides, and vancomy cin (Van) from Streptomyces orientalis and the dipeptide N-acetyl-D-Ala-D-A la. In this procedure a plug of receptor and noninteracting standards is in jected, and analysis of the change in the relative migration time ratio of the receptor, relative to the noninteracting standards, as a function of th e concentration of the ligand yields a value for the binding constant. The findings described here demonstrate that data from ACE studies can best be analyzed using two noninteracting standards, yielding values comparable to those estimated using other binding and ACE techniques. (C) 2000 Academic P ress.