Cytochrome c on Silica Nanoparticles: Influence of Nanoparticle Size on Protein Structure, Stability, and Activity

Authors

  • Wen Shang,

    1. Department of Materials Science and Engineering Rensselaer Nanotechnology Center Rensselaer Polytechnic Institute 110 8th Street, Troy, NY 12180 (USA)
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  • Joseph H. Nuffer,

    1. Department of Chemical and Biological Engineering Department of Biology Rensselaer Nanotechnology Center 4005 Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute, Troy, NY 12180 (USA)
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  • Virginia A. Muñiz-Papandrea,

    1. Department of Chemistry and Chemical Biology Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute, Troy, NY 12180 (USA)
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  • Wilfredo Colón,

    1. Department of Chemistry and Chemical Biology Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute, Troy, NY 12180 (USA)
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  • Richard W. Siegel,

    Corresponding author
    1. Department of Materials Science and Engineering Rensselaer Nanotechnology Center Rensselaer Polytechnic Institute 110 8th Street, Troy, NY 12180 (USA)
    • Department of Materials Science and Engineering Rensselaer Nanotechnology Center Rensselaer Polytechnic Institute 110 8th Street, Troy, NY 12180 (USA).
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  • Jonathan S. Dordick

    Corresponding author
    1. Department of Chemical and Biological Engineering Department of Biology Rensselaer Nanotechnology Center 4005 Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute, Troy, NY 12180 (USA)
    • Department of Chemical and Biological Engineering Department of Biology Rensselaer Nanotechnology Center 4005 Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute, Troy, NY 12180 (USA).
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Abstract

The structure, thermodynamic and kinetic stability, and activity of cytochrome c (cyt c) on silica nanoparticles (SNPs) of different sizes have been studied. Adsorption of cyt c onto larger SNPs results in both greater disruption of the cyt c global structure and more significant changes of the local heme microenvironment than upon adsorption onto smaller SNPs. The disruption of the heme microenvironment leads to a more solvent-accessible protein active site, as suggested by Soret circular dichroism spectroscopy and through an increase in peroxidase activity as a function of increased SNP size. Similarly, the stability of cyt c decreases more dramatically upon adsorption onto larger SNPs. These results are consistent with changes in protein–nanoparticle interactions that depend on the size or surface curvature of the supporting nanostructure. This study provides further fundamental insights into the effects of nanoscale surfaces on adsorbed protein structure and function.

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