Biophysical Society Conference | Tahoe 2024

Molecular Biophysics of Membranes

Poster Abstracts

6-POS Board 12 FUSION OF COARSE GRAINED, IMPLICIT-SOLVENT LIPID MEMBRANES WITH VARIABLE GAUSSIAN CURVATURE MODULI Seamus Gallagher 1 ; Markus Deserno 1 ; 1 Carnegie Mellon Univ, Dept Physics, Pittsburgh, PA, USA The Gauss-Bonnet theorem states that the total Gaussian curvature over a closed membrane is a topological invariant. This suggests the Gaussian curvature modulus is important for topology changing events such as fusion. In support of this point, recent experiments show lipid nanoparticles (LNPs) prepared with lipids that demonstrate a preference towards negative Gaussian curvature phases more readily fuse with the endosome, escaping a well known bottleneck in the LNP drug delivery pathway. To complement these experimental results in simulation, we used a coarse grained lipid model in which we succeeded to prepare a set of lipids with systematically varying Gaussian curvature moduli independently of other elastic parameters and subsequently studied the fusion propensity of such membranes. While our model is well equipped to characterize elastic determinants of fusion, limitations of the implicit solvent used in our model indicate caution is required when hydration dynamics are important.

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