Improving the binding capacity of Ni2+ decorated porous magnetic silica spheres for histidine-rich protein separation

Abstract

The complete elimination of enzymes from the reaction mixture and the possibility of its recycling for several rounds results in great benefits, allowing the reduction of the enzyme consumption and their usability in continuous processes. In this work it is evaluated the capture of a H6-Tagged GFP (GFP-H6) protein on porous magnetic spheres using the Co2+ and Ni 2+ affinity adsorption as a cost effective and up scaled alternative way for the immobilization of his-tagged protein. For this propose, Porous Magnetic Silica (PMS) spheres were synthesised by one step hydrothermal assisted modified-Stöber method. The obtained spheres show a homogeneous size distribution of 400 nm diameter. The y-Fe2O3 nanoparticles are homogeneously distributed in the silica matrix. The obtained PMS spheres have a saturation magnetization of about 10 emu/g and a a total separation time of 16 min at 60 T/m was measured by magnetophoresis. The obtained PMS spheres were successfully and homogeneously decorated with Co2+ and Ni 2+ and then evaluated for the capture of a GFP-H6 protein. The results were compared with the performance of the commercial beads Dynabeads® His-Tag Isolation & Pulldown.