This Materials World Network award from the Division of Materials Research to the University of California, Santa Barbara (UCSB) will support a collaborative computational/experimental project to obtain a fundamental understanding of peptide-peptide interactions. This study combines state-of-the-art atomic force microscopy (AFM) hand-in-hand with advanced molecular simulation studies to obtain atomic-scale insights into peptide-peptide interactions and, in particular, their ability to mediate interactions at solid/liquid interfaces. Using a uniquely flexible model peptide repeat scaffold, precisely controllable sequences and numbers of interacting peptides will be examined, whereby interactions and cooperativities can be tuned with exacting control. Targeted mutations will vary hydrophobicity, charge, and backbone flexibility. Detailed AFM measurements will be compared to molecular pictures developed by equilibrium, quantitative all-atom simulations that probe true underlying, equilibrium interaction landscapes. In particular, the balance between hydrophobic and charge interactions and the effect of cooperative, multi-peptide interactions will be studied in a systematic and hierarchical manner. Simulations will be performed at UCSB, while experiments will be conducted in the group of collaborator Dr. Markus Valtiner at Max-Planck-Institut fur Eisenforschung GmbH in Dusseldorf, Germany.
NON-TECHNICAL SUMMARY: Peptides have emerged as an important class of biocompatible, environmentally friendly, sustainable material alternatives. They can be engineered as tissue scaffolds, biosensors, drug delivery agents, sacrificial templates for nanomaterials, and surface decorants that impart protecting, hydrophobic, antibiotic, or adhesive capabilities. However, their rational engineering is limited by lack of a detailed understanding of the ways in which their many distinct molecular interactions act in concert or competition to produce complex behavior. This work aims to provide a new fundamental understanding of peptide interactions that will establish a baseline for rational peptide engineering strategies. Thus, this project has the potential to significantly influence the next generation of peptide materials, including new high-performance and environmentally friendly nanoscaffolds, glues, and adhesives. This international collaboration brings together two groups with complementary expertise in experimental interfacial science and molecular simulation. Moreover, the research environment will provide outstanding educational opportunities; in particular, project graduate and undergraduate students will benefit from an extensive cross-visitation and research rotation plan. As a part of this work, Prof. Shell will also develop a two-week tutorial course on simulations, including the results of this study, which will be given during an extended rotation in Germany.
