REPEATED USE OF A HYDROPHOBIC LIGAND-CONTAINING POROUS MEMBRANE FOR PROTEIN RECOVERY

A porous hollow-fiber membrane containing a phenyl group as a hydropho bic ligand was prepared by radiation-induced graft polymerization of g lycidyl methacrylate, followed by successive ring-opening reactions wi th phenol and water. Bovine serum albumin (BSA) was bound to the ligan d during permeation of a BSA solution in phosphate buffer containing 2 M (NH4)(2)SO4 through the pores of the hollow fiber. Subsequent eluti on with an (NH4)(2)SO4-free buffer exhibited an elution percentage of 82%. Repeated cycles of adsorption and elution caused the accumulation of BSA on the pore surface, resulting in a decrease in the binding ca pacity of BSA with increasing number of cycles, In contrast, by permea ting 1 M NaOH after each elution, the binding capacity of BSA was main tained even after ten cycles. This alkaline regeneration was found to be effective in ensuring repeated use of the phenyl-group-containing p orous membrane for recovery of proteins.