C@Fe 3O 4/NTA-Ni magnetic nanospheres purify histidine-tagged fetidin: A technical note

This study reports synthesis of Ni-nitrilotriacetic acid (Ni-NTA) modified carbon nanospheres containing magnetic Fe3O4 particles (C@Fe3O4), which can act as a general tool to separate and purify histidine-tagged fetidin. In this experiment, C nanospheres are prepared from glucose using the hydrothermal process, magnetic Fe3O4 are packed in the porous C nanospheres and Ni-NTA are conjugated to C@Fe3O4. C@Fe3O4/NTA-Ni nanospheres are about 400 nm in diameter, providing the nanospheres with excellent magnetic response and dispersity. This study separates recombinant fetidin that are engineered to have six consecutive histidine residues (6xHis) by treating with C@Fe3O4/NTA-Ni magnetic nanospheres. 10 mg of C@Fe3O4/NTA-Ni nanospheres can purify up to 2.103 mg of high-purity 6xHis-tagged fetidin from 10 ml of crude Escherichia coli lysates. Because of high performance,