Title

Effect of Co-Solvents on the Adsorption of Peptides at the Solid-Liquid Interface

Abstract

The adsorption of a peptide at solid surfaces is the result of a complex interplay of interactions between the peptide, solvent, and surface. In this work, Monte Carlo simulations were performed to evaluate the effect of the solvent hydrogen bonding ability on the adsorption of the peptide ASP1-ASP2-ILE3-ILE4-ASP5-ASP6-ILE7-ILE8 at a charged surface consisting of CH2 atoms with a fixed lattice arrangement. Various water-alcohol mixtures were used as solvent because alcohols are known to alter the dielectric constant, hydrophobicity, and hydrogen bonding capacity of water. Solvent-solvent, solvent-surface, solvent-peptide, and peptide-surface interactions were studied independently and correlated with the observed peptide behavior at the solvent-surface interface. We concluded that the behavior (and orientation) of the peptide at the surface is directly related to changes in water-water hydrogen bonding properties in water-alcohol mixtures. In the presence of increasing concentrations of methanol, the strength of solvent-peptide and solvent-surface interactions was reduced, and as a result, a stronger interaction between the peptide and the surface was observed. Stronger solvent-peptide and solvent-surface interactions were responsible for a weaker interaction of the peptide with the surface in the presence of increasing concentrations of glycerol. These results suggest that by changing solvent conditions it is possible to finely tune the orientation of a macromolecule at solid/liquid interfaces.

Department(s)

Chemical and Biochemical Engineering

Sponsor(s)

National Science Foundation (U.S.)

Keywords and Phrases

Adsorption; Cosolvents; Peptides; Macromolecule

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 American Chemical Society (ACS), All rights reserved.


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