EXPERIMENTAL STUDIES IN METAL AFFINITY DISPLACEMENT CHROMATOGRAPHY OFPROTEINS

Metal affinity displacement chromatography was employed for the purifi cation of proteins. The mobile phase modifier imidazole was shown to e xhibit complex induced gradients in these displacement systems resulti ng in different imidazole microenvironments in each protein displaceme nt zone. Furthermore, the induced imidazole gradient produced an eleva ted displacer concentration at the rear of the displacement train. Whi le adsorption isotherms measured under the initial carrier conditions were unable to predict these displacements, isotherms measured under t he induced imidazole conditions qualitatively predicted the effluent d isplacement profiles. It is believed that these induced imidazole grad ients speed up the kinetics of the displacement process and are in par t responsible for the sharp boundaries seen in these separations. This work demonstrates the ability of this bioseparation technique to effe ct efficient multicomponent separations and illustrates the importance of mobile phase modifier effects in metal affinity displacement chrom atography.