Chemistry of aqueous silica nanoparticle surfaces and the mechanism of selective peptide adsorption

Siddharth Patwardhan, Fateme S. Emami, Rajiv J. Berry, Sharon E. Jones, Rajesh. R. Naik, Olivier Deschaume, Hendrik Heinz, Carole C. Perry

Research output: Contribution to journalArticle

229 Citations (Scopus)

Abstract

Control over selective recognition of biomolecules on inorganic nanoparticles is a major challenge for the synthesis of new catalysts, functional carriers for therapeutics, and assembly of renewable biobased materials. We found low sequence similarity among sequences of peptides strongly attracted to amorphous silica nanoparticles of various size (15-450 nm) using combinatorial phage display methods. Characterization of the surface by acid base titrations and zeta potential measurements revealed that the acidity of the silica particles increased with larger particle size, corresponding to between 5% and 20% ionization of silanol groups at pH 7. The wide range of surface ionization results in the attraction of increasingly basic peptides to increasingly acidic nanoparticles, along with major changes in the aqueous interfacial layer as seen in molecular dynamics simulation. We identified the mechanism of peptide adsorption using binding assays, zeta potential measurements, IR spectra, and molecular simulations of the purified peptides (without phage) in contact with uniformly sized silica particles. Positively charged peptides are strongly attracted to anionic silica surfaces by ion pairing of protonated N-termini, Lys side chains, and Arg side chains with negatively charged siloxide groups. Further, attraction of the peptides to the surface involves hydrogen bonds between polar groups in the peptide with silanol and siloxide groups on the silica surface, as well as ion-dipole, dipole-dipole, and van-der-Waals interactions. Electrostatic attraction between peptides and particle surfaces is supported by neutralization of zeta potentials, an inverse correlation between the required peptide concentration for measurable adsorption and the peptide pI, and proximity of cationic groups to the surface in the computation. The importance of hydrogen bonds and polar interactions is supported by adsorption of noncationic peptides containing Ser, His, and Asp residues, including the formation of multilayers. We also demonstrate tuning of interfacial interactions using mutant peptides with an excellent correlation between adsorption measurements, zeta potentials, computed adsorption energies, and the proposed binding mechanism. Follow-on questions about the relation between peptide adsorption on silica nanoparticles and mineralization of silica from peptide-stabilized precursors are raised.

LanguageEnglish
Pages6244-6256
Number of pages13
JournalJournal of the American Chemical Society
Volume134
Issue number14
Early online date21 Mar 2012
DOIs
Publication statusPublished - 11 Apr 2012

Fingerprint

Silicon Dioxide
Nanoparticles
Peptides
Adsorption
Silica
Zeta potential
Bacteriophages
Ionization
Hydrogen
Hydrogen bonds
Ions
Biomolecules
Molecular Dynamics Simulation
Static Electricity
Titration
Particle Size
Acidity
Molecular dynamics
Electrostatics
Assays

Keywords

  • inorganic nanoparticles
  • nanoparticle surfaces
  • peptides

Cite this

Patwardhan, S., Emami, F. S., Berry, R. J., Jones, S. E., Naik, R. R., Deschaume, O., ... Perry, C. C. (2012). Chemistry of aqueous silica nanoparticle surfaces and the mechanism of selective peptide adsorption. Journal of the American Chemical Society, 134(14), 6244-6256. https://doi.org/10.1021/ja211307u
Patwardhan, Siddharth ; Emami, Fateme S. ; Berry, Rajiv J. ; Jones, Sharon E. ; Naik, Rajesh. R. ; Deschaume, Olivier ; Heinz, Hendrik ; Perry, Carole C. / Chemistry of aqueous silica nanoparticle surfaces and the mechanism of selective peptide adsorption. In: Journal of the American Chemical Society. 2012 ; Vol. 134, No. 14. pp. 6244-6256.
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Patwardhan, S, Emami, FS, Berry, RJ, Jones, SE, Naik, RR, Deschaume, O, Heinz, H & Perry, CC 2012, 'Chemistry of aqueous silica nanoparticle surfaces and the mechanism of selective peptide adsorption' Journal of the American Chemical Society, vol. 134, no. 14, pp. 6244-6256. https://doi.org/10.1021/ja211307u

Chemistry of aqueous silica nanoparticle surfaces and the mechanism of selective peptide adsorption. / Patwardhan, Siddharth; Emami, Fateme S.; Berry, Rajiv J.; Jones, Sharon E.; Naik, Rajesh. R.; Deschaume, Olivier; Heinz, Hendrik; Perry, Carole C.

In: Journal of the American Chemical Society, Vol. 134, No. 14, 11.04.2012, p. 6244-6256.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Chemistry of aqueous silica nanoparticle surfaces and the mechanism of selective peptide adsorption

AU - Patwardhan, Siddharth

AU - Emami, Fateme S.

AU - Berry, Rajiv J.

AU - Jones, Sharon E.

AU - Naik, Rajesh. R.

AU - Deschaume, Olivier

AU - Heinz, Hendrik

AU - Perry, Carole C.

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N2 - Control over selective recognition of biomolecules on inorganic nanoparticles is a major challenge for the synthesis of new catalysts, functional carriers for therapeutics, and assembly of renewable biobased materials. We found low sequence similarity among sequences of peptides strongly attracted to amorphous silica nanoparticles of various size (15-450 nm) using combinatorial phage display methods. Characterization of the surface by acid base titrations and zeta potential measurements revealed that the acidity of the silica particles increased with larger particle size, corresponding to between 5% and 20% ionization of silanol groups at pH 7. The wide range of surface ionization results in the attraction of increasingly basic peptides to increasingly acidic nanoparticles, along with major changes in the aqueous interfacial layer as seen in molecular dynamics simulation. We identified the mechanism of peptide adsorption using binding assays, zeta potential measurements, IR spectra, and molecular simulations of the purified peptides (without phage) in contact with uniformly sized silica particles. Positively charged peptides are strongly attracted to anionic silica surfaces by ion pairing of protonated N-termini, Lys side chains, and Arg side chains with negatively charged siloxide groups. Further, attraction of the peptides to the surface involves hydrogen bonds between polar groups in the peptide with silanol and siloxide groups on the silica surface, as well as ion-dipole, dipole-dipole, and van-der-Waals interactions. Electrostatic attraction between peptides and particle surfaces is supported by neutralization of zeta potentials, an inverse correlation between the required peptide concentration for measurable adsorption and the peptide pI, and proximity of cationic groups to the surface in the computation. The importance of hydrogen bonds and polar interactions is supported by adsorption of noncationic peptides containing Ser, His, and Asp residues, including the formation of multilayers. We also demonstrate tuning of interfacial interactions using mutant peptides with an excellent correlation between adsorption measurements, zeta potentials, computed adsorption energies, and the proposed binding mechanism. Follow-on questions about the relation between peptide adsorption on silica nanoparticles and mineralization of silica from peptide-stabilized precursors are raised.

AB - Control over selective recognition of biomolecules on inorganic nanoparticles is a major challenge for the synthesis of new catalysts, functional carriers for therapeutics, and assembly of renewable biobased materials. We found low sequence similarity among sequences of peptides strongly attracted to amorphous silica nanoparticles of various size (15-450 nm) using combinatorial phage display methods. Characterization of the surface by acid base titrations and zeta potential measurements revealed that the acidity of the silica particles increased with larger particle size, corresponding to between 5% and 20% ionization of silanol groups at pH 7. The wide range of surface ionization results in the attraction of increasingly basic peptides to increasingly acidic nanoparticles, along with major changes in the aqueous interfacial layer as seen in molecular dynamics simulation. We identified the mechanism of peptide adsorption using binding assays, zeta potential measurements, IR spectra, and molecular simulations of the purified peptides (without phage) in contact with uniformly sized silica particles. Positively charged peptides are strongly attracted to anionic silica surfaces by ion pairing of protonated N-termini, Lys side chains, and Arg side chains with negatively charged siloxide groups. Further, attraction of the peptides to the surface involves hydrogen bonds between polar groups in the peptide with silanol and siloxide groups on the silica surface, as well as ion-dipole, dipole-dipole, and van-der-Waals interactions. Electrostatic attraction between peptides and particle surfaces is supported by neutralization of zeta potentials, an inverse correlation between the required peptide concentration for measurable adsorption and the peptide pI, and proximity of cationic groups to the surface in the computation. The importance of hydrogen bonds and polar interactions is supported by adsorption of noncationic peptides containing Ser, His, and Asp residues, including the formation of multilayers. We also demonstrate tuning of interfacial interactions using mutant peptides with an excellent correlation between adsorption measurements, zeta potentials, computed adsorption energies, and the proposed binding mechanism. Follow-on questions about the relation between peptide adsorption on silica nanoparticles and mineralization of silica from peptide-stabilized precursors are raised.

KW - inorganic nanoparticles

KW - nanoparticle surfaces

KW - peptides

U2 - 10.1021/ja211307u

DO - 10.1021/ja211307u

M3 - Article

VL - 134

SP - 6244

EP - 6256

JO - Journal of the American Chemical Society

T2 - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 14

ER -