COMPARISON OF 5 METHODS FOR THE STUDY OF DRUG-PROTEIN BINDING IN AFFINITY CAPILLARY ELECTROPHORESIS

The qualitative and quantitative aspects of capillary electrophoretic methods used to study drug-protein interactions, viz. the affinity cap illary electrophoresis (ACE), Hummel-Dreyer (HD), frontal analysis (FA ), vacancy peak (VP) and vacancy affinity capillary electrophoresis (V ACE) methods have been investigated. In the ACE and the VACE methods t he binding parameters can be calculated from the change in the electro phoretic mobility of the drug on complexation with a protein. In the f rontal analysis and the vacancy peak method the free drug concentratio n is measured with UV detection. In the Hummel-Dreyer method the amoun t of drug bound is measured with UV detection. For the comparison of t hese five methods the warfarin-bovine serum albumin (BSA) system was u sed. Several factors that might influence the determination of associa tion parameters were examined. With the FA, VP, HD and VACE methods th e absolute numbers of the different binding sites involved in the comp lex formation can be determined, a major advantage in drug-binding stu dies. (C) 1997 Elsevier Science B.V.