Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads for magnetic affinity separation of histidine-tagged proteins

Dalton Trans. 2016 Jan 28;45(4):1582-92. doi: 10.1039/c5dt03827h.

Abstract

Magnetic Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads (Ni-ferrosphere beads - NFB) of a core-shell structure were synthesized starting from coal fly ash ferrospheres having diameters in the range of 0.063-0.050 mm. The strategy of NFB fabrication is an oriented chemical modification of the outer surface preserving the magnetic core of parent beads with the formation of micro-mesoporous coverings. Two routes of ferrosphere modification were realized, such as (i) hydrothermal treatment in an alkaline medium resulting in a NaP zeolite layer and (ii) synthesis of micro-mesoporous silica on the glass surface using conventional methods. Immobilization of Ni(2+) ions in the siliceous porous shell of the magnetic beads was carried out via (i) the ion exchange of Na(+) for Ni(2+) in the zeolite layer or (ii) deposition of NiO clusters in the zeolite and silica pores. The final NFB were tested for affinity in magnetic separation of the histidine-tagged green fluorescent protein (GFP) directly from a cell lysate. Results pointed to the high affinity of the magnetic beads towards the protein in the presence of 10 mM EDTA. The sorption capacity of the ferrosphere-based Ni-beads with respect to GFP was in the range 1.5-5.7 mg cm(-3).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Escherichia coli / chemistry
  • Escherichia coli / cytology
  • Green Fluorescent Proteins / chemistry
  • Green Fluorescent Proteins / isolation & purification*
  • Histidine / chemistry*
  • Iron Compounds / chemistry*
  • Magnetic Phenomena
  • Nickel / chemistry*
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Particle Size
  • Porosity
  • Scyphozoa
  • Silicon Dioxide / chemistry*
  • Surface Properties
  • Zeolites / chemistry*

Substances

  • Iron Compounds
  • Organometallic Compounds
  • Zeolites
  • Green Fluorescent Proteins
  • Histidine
  • Silicon Dioxide
  • Nickel