PMSE 180 |
| Short peptides (8 to 12 amino acids, excluding Cys) bind selectively to nanoparticles composed of Au, Pd, or montmorillonite depending on the sequence of amino acids, as evidenced by screening of several billion peptides using phage-display techniques. The molecular reasons for binding versus non-binding and the specificity toward a certain surface are analyzed by molecular dynamics simulation. First, we highlight the importance of force field parameters for metals and silicates and show that surface and interface energies for fcc metals and sheet silicates can be reproduced with deviations of less than 10% compared to experiment. On even metal surfaces, the amount of polarization due to induced charges in the metal is found to be in the range 3 to 5 kcal/mol per dodecapeptide (12 amino acids), which is about an order of magnitude smaller than corresponding non-covalent binding energies. The analysis of the adsorption energies, changes in chain conformation relative to solution, Ramachandran plots, and orientational parameters provide first suggestions on the mechanism of binding to metals. On montmorillonite nanoparticles, a significant interaction between alkali cations and polar groups in the peptide is seen and the exchange of Lys side groups against alkali ions is observed as an important factor for binding. |
|
Synthesis and Self-Assembly Approaches to Polymer-Inorganic Hybrid Nanoparticles
1:30 PM-4:30 PM, Tuesday, April 8, 2008 Hilton New Orleans Riverside -- Grand Salon 24, Oral
Division of Polymeric Materials: Science & Engineering |