M13 Bacteriophage-Activated Superparamagnetic Beads for Affinity Separation

Authors

  • Julien Muzard,

    1. UCD Centre for Nanomedicine, School of Chemistry & Chemical Biology - University, College Dublin Belfield, Dublin 4, Ireland
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  • Mark Platt,

    1. UCD Centre for Nanomedicine, School of Chemistry & Chemical Biology - University, College Dublin Belfield, Dublin 4, Ireland
    Current affiliation:
    1. Analytical Chemistry Department, Loughborough University, UK.
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  • Gil U. Lee

    Corresponding author
    1. UCD Centre for Nanomedicine, School of Chemistry & Chemical Biology - University, College Dublin Belfield, Dublin 4, Ireland
    • UCD Centre for Nanomedicine, School of Chemistry & Chemical Biology - University, College Dublin Belfield, Dublin 4, Ireland.
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Abstract

The growth of the biopharmaceutical industry has created a demand for new technologies for the purification of genetically engineered proteins.The efficiency of large-scale, high-gradient magnetic fishing could be improved if magnetic particles offering higher binding capacity and magnetization were available. This article describes several strategies for synthesizing microbeads that are composed of a M13 bacteriophage layer assembled on a superparamagnetic core. Chemical cross-linking of the pVIII proteins to a carboxyl-functionalized bead produces highly responsive superparamagnetic particles (SPM) with a side-on oriented, adherent virus monolayer. Also, the genetic manipulation of the pIII proteins with a His6 peptide sequence allows reversible assembly of the bacteriophage on a nitrilotriacetic-acid-functionalized core in an end-on configuration. These phage–magnetic particles are successfully used to separate antibodies from high-protein concentration solutions in a single step with a >90% purity. The dense magnetic core of these particles makes them five times more responsive to magnetic fields than commercial materials composed of polymer–(iron oxide) composites and a monolayer of phage could produce a 1000 fold higher antibody binding capacity. These new bionanomaterials appear to be well-suited to large-scale high-gradient magnetic fishing separation and promise to be cost effective as a result of the self-assembling and self-replicating properties of genetically engineered M13 bacteriophage.

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