Magnetic affine sorbents for the isolation of recombinant proteins

Abstract

An affine sorbent of the “core–shell” type was prepared on the basis of fly ash ferrospheres with the aluminosilicate glass phase content of 41 wt % as a magnetic core. The synthesis of the functional coating included four steps: the steam treatment of the fraction, the synthesis of a mesoporous silica coating on the ferrospheres surface, the surface activation by boiling in an alkaline medium, and the subsequent immobilization of Ni²⁺ ions on the surface of modified ferrospheres by impregnation. The modified ferrospheres were characterized by the methods of simultaneous thermal analysis, infrared spectroscopy, X-ray diffraction, and low-temperature nitrogen adsorption. It was found that the obtained sorbent was characterized by an acceptable strength of binding of the functional shell and the sorption capacity with respect to the green fluorescent protein of up to 6.7 mg/cm³. The stability of the sorbent in repeated use was studied. It was established that the sorption capacity after the seventh cycle was stabilized at the level of 70% of the initial capacity.