228a Atomistic and Coarse Grained Simulation of the Aggregation of Beta-Peptides in Solution

Clark A. Miller1, Samuel H. Gellman2, and Juan J. De Pablo1. (1) Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706-1691, (2) Department of Chemistry, University of Wisconsin-Madison, 1101 Univeristy Avenue, Madision, WI 53706

We study the aggregation of beta-peptides on a variety of length scales using Monte Carlo and molecular dynamics simulations. We begin by exploring a single peptide in explicit solvent and find it to form a stable 14 member helix. Next we study the behavior of multiple peptides in explicit and implicit solvent and prove the validity of using an implicit solvent model. The potential of mean force between two peptides shows a preference for the aggregation at particular orientations and distances. A coarse grained model of the peptides is developed with a Lennard-Jones and a point dipole potential. The phase behavior, including a polymerization transition and two coexisting phases, is then determined for the beta-peptides using the coarse grained model.