Affinity Chromatography and its Application

Preparation of new affinity adsorbents

Abstract

The most widely used means of preparing affinity adsorbents is the CNBr method by Axén et. al.. Unfortunately, the adsorbents prepared by this method have serious disadvantages : the non-specific adsorption and the leakage of the ligand. The nonspecific adsorption is due to the ion-exchanging properties of isourea derivatives formed between ligand and agarose and can be avoided by using hydrazides for the binding on CNBr-activated agarose. The leakage of the ligand is attributed to the instability of the isourea bond and can be prevented by using polyvalent spacers. Polyacrylhydrazido-agarose has been used for these reasons. The epoxy method has been used to prepare the adsorbents without these problems. However, another problem is encountered with this method, the requirement for high temperature and/or hight pH during the coupling step. To circumvent this problem, the new procedure has been devised for the conversion of epoxy group into more reactive group. The preparation of the adsorbents by these methods and their application to affinity chromatography are presented in this paper.