All-atom molecular dynamics is a powerful tool in understanding molecular-level events accompanying protein-surface interactions. However, current force fields have not been validated for this use. We have calculated free energy of adsorption (?Gads) of small host-guest peptides (TGTG-X-GTGT, where X represents 8 different amino-acids from primary characteristic types) on three surfaces (high-density polyethylene, poly(methyl-methacrylate), and silica glass) using CHARMM force field and compared these ?Gads values to experimental results in order to identify errors in force-field parameterization for adsorption behavior. We use an in-house developed dual-force-field approach implemented in CHARMM, which employs two independent sets of nonbonded parameters: one for intraphase interactions (i.e., within solution or material phases) and another for interphase interactions (i.e., between solution and material phases). Nonbonded parameters for the interphase interactions are then modified to match ?Gads to experimental data. Following force field parameter adjustment and validation, simulations can be performed to accurately predict protein adsorption.

Accurate molecular dynamics simulation of peptide adsorption to polyethylene, poly(methyl-methacrylate), and silica surfaces using dual-force-field in CHARMM

244th National Meeting (2012)

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