SEMIPREPARATIVE PURIFICATION OF AN ENDOGENOUS LIGAND FOR BRAIN SEROTONIN-2 RECEPTORS BY COIL PLANET CENTRIFUGE COUNTERCURRENT CHROMATOGRAPHY

A horizontal flow-through coil planet centrifuge equipped with a rotatory frame holding three sets of composite column assemblies was used for purification of an endogenous ligand (ketanserin binding inhibitor) for the [H-3]-ketanserin (H-3-KET) recognition site. The protein mixture containing the endogenous material was successfully resolved by using a two-phase solvent system consisting of 95% ethanol-31.5% ammonium sulphate (1:2). The active fractions on H-3-KET binding obtained after counter-current chromatography (CCC) were further purified through a C18-mu-Bondapak reversed-phase high-pressure liquid chromatographic column. The introduction of this advanced CCC technique represents an important step in the application of CCC for the separation of polar proteins from protein mixtures.