Biophysical Society Thematic Meeting | Hamburg 2022

Biophysics at the Dawn of Exascale Computers

Poster Abstracts

61-POS Board 61 TOPOLOGY, LANDSCAPES, AND BIOMOLECULAR ENERGY TRANSPORT Michael Zwolak 1 ; Justin Elenewski 1 ; Kirill Velizhanin 2 ; 1 National Institute of Standards and Technology, Biophysical and Biomedical Measurement, Gaithersburg, MD, USA 2 Los Alamos National Laboratory, Theoretical Division, Los Alamos, NM, USA The objective of our work is to employ transient data, such as that given by ultrafast spectroscopic measurements of energy transport, to extract features of biomolecular landscapes and topology. We use replica-exchange and non-equilibrium molecular dynamics to study a large set of structural conformations within the microcanonical ensemble. Internal energy transport exhibited a new phenomenon - nonlinear localization - due to what is in essence an impedance mismatch of different regions of the biomolecular landscape. [Nature Communications 10, 4662 (2019)] While ubiquitous, energy redistribution remains a poorly understood facet of the nonequilibrium thermodynamics of biomolecules. At the molecular level, finite-size effects, pronounced nonlinearities, and ballistic processes conspire to produce behavior that diverges from the macroscale. Here, we show that transient thermal transport reflects macromolecular energy landscape architecture through both (i) the topological characteristics of the conformational ensemble and (ii) the nonlinear processes that mediate dynamics. While the former determines transport pathways via molecular contacts, the latter reflects the ruggedness of the landscape for local motion of atoms and molecular fragments. Unlike transport through small-molecule systems, such as alkanes, nonlinearity dominates over coherent processes at even quite short time- and length-scales. Our exhaustive all-atom simulations and novel local-in-time and space analysis, applicable to both theory and experiment, permit dissection of energy migration in biomolecules. The approach demonstrates that vibrational energy transport can probe otherwise inaccessible aspects of macromolecular dynamics and interactions that underly biological function.

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