Separation of proteins by polymeric adsorbents containing azobenzene moiety as a ligand

Abstract

AbstractPolymeric adsorbents containing an azobenzene moiety as a ligand were prepared, and the photoinduced adsorption behavior of proteins to the adsorbent was studied. This method regulates by light the adsorption/desorption of proteins in hydrophobic chromatography. In the dark, the amount of protein adsorbed onto the adsorbent increased with increasing hydrophobicity of either adsorbent or protein. On irradiation with UV light, the amount of protein adsorbed decreased. Such a photoinduced change of the adsorption of protein was considered to be caused by the change of the hydrophobic interaction between the adsorbent and the protein due to the photoisomerization of the azobenzene moiety accompanying the polarity change of the adsorbent. It is also found that the desorption of protein was dependent on the balance of the hydrophobicity between the adsorbents and proteins. When column chromatography was carried out, the proteins were adsorbed in the dark and could be eluted after photoirradiation, with water as the single solvent. Furthermore, mixture of proteins could be separated by using a hydrophobic gradient column which was constituted by two polymeric adsorbents having different hydrophobicity.