(756e) Computational Analysis of Beta-Peptide Self-Assembly

β-peptides are a class of
synthetic oligomers that are capable of folding in precise patterns.  The wide variety of side chains that are available for insertion into β-peptide
sequences along with the stability of these folded secondary structures allow
precise control over the nanoscale presentation of
various chemical functional groups in three dimensional space.  Some β-peptides have been shown to
spontaneously fold into complex supramolecular structures, and others have been
shown to be effective antimicrobial agents that are believed to act by
aggregating in certain types of cell membranes. 
However, more work is needed to understand what drives this assembly in
order to design β-peptides that assemble in particular ways.  Using molecular simulations, the process of
β-peptide aggregation is examined in a variety of environments that allow
for direct comparison to experiment. 
Using new simulation techniques, the structure of the aggregates formed
by several β-peptides are predicted in both bulk solutions, and at
interfaces.  Free energy surfaces are
generated using multiple geometric parameters to directly compare the
favorability of different modes of aggregation, and pressure area isotherms are
calculated for β-peptide monolayers and compared to experiments.  By analyzing these results, we gain an
understanding of the factors that drive self-assembly and aggregation.