Adsorption of homopolypeptides on gold investigated using atomistic molecular dynamics

We investigate the role of dynamics on adsorption of peptides to gold surfaces using all-atom molecular dynamics simulations in explicit solvent. We choose six homopolypeptides [Ala 10 , Ser 10 , Thr 10 , Arg 10 , Lys 10 , and Gln 10 ], for which experimental surface coverages are not correlated with amino acid level affinities for gold, with the idea that dynamic properties may also play a role. To assess dynamics we determine both conformational movement and flexibility of the peptide within a given conformation. Low conformational movement indicates stability of a given conformation and leads to less adsorption than homopolypeptides with faster conformational movement. Likewise, low flexibility within a given conformation also leads to less adsorption. Neither amino acid affinities nor dynamic considerations alone predict surface coverage; rather both quantities must be considered in peptide adsorption to gold surfaces.US Department of Energy, Office of Advanced Scientific Computing; grant number DE-FG02-02ER25535. Foundation for Science and Technology for post-doctoral fellowship SFRH/BPD/20555/2004/0GVL. USA National Science Foundation Grant # EEC-0353569 for participation in the REU program in Biomolecular Engineering