Multifunctional polymer-derivatized gamma-Fe(2)O(3) nanocrystals as a methodology for the biomagnetic separation of recombinant His-tagged proteins

Multifunctional polymer-derivatized superparamagnetic iron oxide (gamma-Fe(2)O(3)) nanoparticles were prepared for biomagnetic separation of histidine-tagged recombinant proteins building up a faster and efficient method for protein separation by making use of their intrinsic magnetic properties. Using polymer bound gamma-Fe(2)O(3) nanocrystals, a 6 x histidine-tagged recombinant protein (silicatein) with a molecular weight of 24 kDa has been isolated and purified. The supermagnetic iron oxide nanocrystals were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), SQUID and Mossbauer and the polymer functionalization of the gamma-Fe(2)O(3) nanocrystals was monitored by UV-vis spectroscopy and light microscopy. Protein immobilization and separation was monitored using immunostaining techniques and gel electrophoresis, respectively. (C) 2008 Elsevier B.V. All rights reserved.