Chemistry and Biochemistry Seminar - Jianing Li, PhD, University of Vermont, "Multiscale Modeling of Peptide Self-Assembly"

Wednesday, April 03, 2019
12:00 pm
Floor/Room #: 

Multiscale Modeling of Peptide Self-Assembly

Modeling peptide assembly from monomers is often intractable at the atomistic resolution on large time and length scales. To address this challenge, we present a new approach which integrates coarse-grained (CG), mixed-resolution, and all‑atom (AA) modeling in a single simulation. We simulate the initial encounter stage with the CG model, while the further assembly and reorganization stages are simulated with the mixed-resolution and AA models.We have implemented this top-down approach with new tools to automate model transformations and to monitor oligomer formations. Further, a theory was developed to estimate the optimal simulation length for each stage using a model peptide, melittin. The assembly level, the oligomer distribution, and the secondary structures of melittin simulated by the optimal protocol show good agreement with prior experiments and AA simulations. Finally, our approach and theory have been successfully validated with three amyloid peptides (β-amyloid 16-22, GNNQQNY fragment from the yeast prion protein SUP35, and α-synuclein fibril 35-55), which highlight the synergy from modeling at multiple resolutions. This work not only serves as proof of concept for multi-resolution simulation studies, but also presents practical guidelines for further self-assembly simulations at more physically and chemically relevant scales.