Abstract
We proposed a method for purifying proteins based on an interaction between dually-immobilized affinity ligands and dually-tagged proteins. Streptavidin (SA) and nickel (Ni) ions as two kinds of ligands were immobilized to the polymer brush grafted onto a porous hollow-fiber membrane. Whereas, green fluorescent protein (GFP) containing both streptavidin binding peptide (SBP) and poly histidine tag (His-tag) as two kinds of tags was genetically produced. The resultant dually-tagged protein solution was permeated through the pores of the dual-affinity-ligands- immobilized porous hollow-fiber membrane. The dual-affinity ligands and dually-tagged proteins were found to fit on the polymer chain grafted onto the pore surface at a binding efficiency 2%.
