Biophysical Society Conference | Tahoe 2022

Molecular Biophysics of Membranes

Poster Abstracts

15-POS Board 4 SIMULATIONS OF MICRON-SCALE CURVATURE SENSING Christopher Edelmaier 1 ; Wenzheng Shi 1 ; Brandy Curtis 2 ; Amy Gladfelter 2,3 ; Ehssan Nazockdast 1 ; 1 UNC Chapel Hill, Applied Physics, Chapel Hill, NC, USA Cells use their cytoskeletal elements to perform many functions, including sensing and adapting to their environment. One such class of proteins are septins, which can sense and communicate details about micron-scale curvature based on their binding to cellular membranes. Amphipathic helix (AH) domains are thought to be responsible for the ability of these nanoscale proteins to probe micron-scale curvatures by sensing local curvature effects. Previous studies have investigated similar domains in other contexts (other AH-domains and BAR-domains), however, much of the understanding relies on kinetic models that effectively capture the phenomenology at the micron-scale of this interaction but cannot give a description of the underlying mechanical interactions that lead to these kinetic descriptions. One barrier to understanding these mechanical effects from simulations is the difference in time scale(s) between atomistic, coarse-grained, and continuum simulations when compared to in vivo or in vitro septin binding rates. Here, we present preliminary research into how AH-domains might interact with lipid bilayer membranes at both the atomistic and coarse-grained level to understand how these domains associate with membranes, change local membrane properties, and result in the correct binding-rate and curvature specificity seen in cells. 2 UNC Chapel Hill, Biology, Chapel Hill, NC, USA 3 Marine Biological Laboratory, Woods Hole, MA, USA

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