New methods of protein purification. Displacement chromatography.

This review discusses a new method for protein purification, displacement chromatography. Elution of proteins bound to an adsorbent is carried out in displacement chromatography by a substance, the so-called "displacer", which has a higher affinity for the chromatographic matrix than any of the adsorbed proteins. The latter are "pushed out" from the matrix by the displacer and form a displacement train when moving along the column. The component with the weakest affinity moves first, and the one with the highest affinity moves last in the train. The concentration of the component in the displacement zone is determined by the intersection of the operating line and binding isotherm of the given component. The shape of the displacement zone is close to rectangular. A more powerful resolving force is created compared to other methods of selective elution, especially at high column loadings, when nearly the whole working capacity of the column is used. Independence of component concentration in the displacement zone on its content in the feed allows significant concentrating of the purified protein during displacement chromatography. Examples of application of displacement chromatography for the separation of model protein systems and purification of proteins from crude extracts are discussed as well as methods of column regeneration.