REVIEW: New Methods of Protein Purification. Displacement Chromatography
I. Yu. Galaev
Department of Biotechnology, Center for Chemistry and Chemical
Engineering, Lund University, P.O. Box 124, Lund, S-22100, Sweden; fax:
46-46-2224713; E-mail:
biot-iga@hermes.lu.se
Received April 15, 1998
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.
KEY WORDS: protein purification, displacement chromatography