(759a) Molecular Dynamics Simulations of 2D Self-Assembled Peptide Monolayers

Self-assembled peptides offer a wide range of applications in nanotechnology, for example the patterning of interfaces. It has been proposed to use self-assembled peptide β-sheet structures as templates for the nucleation and growth of inorganic materials. In this work, we investigate the self-assembly process of rationally designed periodically sequenced peptides that assemble into β-sheet structures when confined to a 2D air-liquid interface. Leon et al.¹ have examined the electrostatic effect by varying the distance between two residues with the same charges along a peptide; this electrostatic effect changes the morphology of the β-structures. We simulate the formation of β-sheet structures from random coils at the interface using an intermediate-resolution coarse-grained model of the amino acids with discontinuous molecular dynamics (DMD). We validate our coarse-grained model by running single molecule simulations and comparing the folding transition and final conformations with those obtained from CHARMM. Using the experimental results from Leon et al., we compare the structures and packing of the β-structures and the effects of charge localization on the peptide. In addition, we will propose general guidelines for how the placement of electrostatic residues in a peptide affects the assembly of these 2D structures. 

1.  L. Leon, P. Logrippo, R. Tu. Self-Assembly of Rationally Designed Peptides under Two-Dimensional Confinement. Biophysical Journal 2010, 99, 2888-2895.