Related Experiment Videos
Molecular dynamics simulations of peptide-surface interactions.
Vivek P Raut1, Madhuri A Agashe, Steven J Stuart
1Department of Bioengineering and Department of Chemistry, Clemson University, Clemson, South Carolina 29634, USA.
Langmuir : the ACS Journal of Surfaces and Colloids
|February 9, 2005
Summary
Molecular dynamics simulations revealed inaccuracies in the GROMACS force field for predicting peptide adsorption on self-assembled monolayers (SAMs). Rebalancing force field parameters is crucial for accurate simulations of protein-surface interactions and biocompatibility assessments.
Area of Science:
- Biomaterials Science
- Computational Chemistry
- Surface Science
Background:
- Protein adsorption on implants influences biocompatibility through poorly understood mechanisms.
- Molecular dynamics (MD) simulations offer a direct theoretical approach to analyze protein adsorption.
- Existing force fields may not accurately represent peptide-surface interactions, necessitating validation.
Purpose of the Study:
- To develop and assess methods for calculating peptide adsorption free energy using MD simulations.
- To evaluate the accuracy of the GROMACS force field for peptide adsorption on functionalized self-assembled monolayers (SAMs).
- To compare simulation results with experimental data obtained via surface plasmon resonance (SPR) spectroscopy.
Main Methods:
- Utilized a host-guest peptide adsorption model (G(4)-X-G(4)) with variable residues (X).
- Simulated peptide adsorption on gold surfaces functionalized with oligoethylene glycol (OEG), hydroxyl (OH), and carboxyl (COOH) terminated alkanethiols.
- Employed molecular dynamics simulations with the GROMACS force field and compared results to experimental SPR data.
Main Results:
- Simulations showed minimal adsorption to OH-SAMs and strong adsorption of G(4)-K-G(4) to COOH-SAMs, aligning with SPR experiments.
- Contrary to experiments, simulations predicted significant adsorption of G(4)-G(4)-G(4) to COOH-SAMs.
- Unexpectedly, simulations predicted adsorption of both peptides to OEG-functionalized SAMs.
Conclusions:
- The GROMACS force field requires rebalancing of parameters for accurate simulation of peptide adsorption on SAM surfaces.
- The developed methods enable direct assessment, modification, and validation of force field performance for peptide-surface interactions.
- Accurate force fields are essential for reliable MD simulations of protein adsorption and biocompatibility assessments.