CBE Seminar: Multiscale Modeling of Bioelectrocatalytic Cascades

Abstract: Multistep biocatalytic cascades benefit from channeling mechanisms that guide intermediate transport between active sites. Channeling approaches such as electrostatic interactions and steric confinement are best exemplified in natural biocatalytic complexes such as tryptophan synthase and malate dehydrogenase-citrate synthase but are also amenable to application in new cascades designed to accomplish chemical conversion and energy production.

We have approached channeling mechanisms computationally using multi-scale techniques ranging from continuum modeling to molecular dynamics. These tools allow us to quantitatively predict the effect of enzyme structure on channeling efficiency. Starting with continuum models with simplified geometry, we demonstrate the range of kinetic activity over which channeling can be effective. To consider the more complex surface topology and electrostatic fields introduced by enzyme surfaces, we introduce classical molecular dynamics and Markov state models to analyze MD results. To expand the time scales accessible to the models, we employ metadynamics and finite difference models that generate data for validation against experiments. These latter approaches are demonstrated using natural and synthetic model enzyme cascades.

Bio: Scott Calabrese Barton is a professor of Chemical Engineering and Materials Science at Michigan State University. His research focuses on engineering and materials issues in electrochemical systems, particularly kinetics and mass transport in fuel cell electrodes. His work has covered a range of systems, including direct methanol fuel cells, zinc-air batteries, biofuel cell electrodes and electrochemical conversion of organic materials.