Interaction of cyclophilin and cyclosporins monitored by affinity capillary electrophoresis

The affinity capillary electrophoretic separation of the complex of the enzyme cyclophilin (Cyp) with the immunosuppressive drug cyclosporin A (CsA) from uncomplexed Cyp and CsA in phosphate buffer (pH 8) under non-denaturing conditions by equilibrium-mixture analysis is reported. Using a new approach combining mobility-shift analysis and electrophoretically mediated microanalysis the binding constant of rhCyp18 to CsA and derivatives was estimated.