title: Cytochrome C on silica nanoparticles: influence of nanoparticle size on protein structure, stability, and activity.
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.
authors.affiliation: Department of Materials Science and Engineering, Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Shang
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Nuffer
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Muñiz-Papandrea
authors.forename: Wilfredo
authors.initials: W
authors.lastname: Colón
authors.forename: Richard W
authors.initials: RW
authors.lastname: Siegel
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Dordick
mesh_terms: D000327:Adsorption; D045304:Cytochromes c / Q000737:chemistry*; D004795:Enzyme Stability; D053758:Nanoparticles; D010316:Particle Size; D011487:Protein Conformation; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide; D045304:Cytochromes c