Topological transitions of fluid lipid membranes are fundamental processes for cell life. For example, they are required for endo- and exocytosis or to enable neurotransmitters to cross the neural synapses. Here, inspired by the idea that fusion and fission proteins could have evolved in Nature in order to carry out a minimal work expenditure, we evaluate the minimal free energy pathway for the transition between two spherical large unilamellar vesicles and a dumbbell-shaped one. To address the problem, we propose and successfully use a Ginzburg-Landau type of free energy, which allows us to uniquely describe without interruption the whole, full-scale topological change. We also compute the force fields needed to overcome the involved energy barriers. The obtained forces are in excellent agreement, in terms of intensity, scale, and spatial localization with experimental data on typical fission protein systems, whereas they suggest the presence of additional features in fusion proteins.
|Publication status||Published - 12 Nov 2022|
Bibliographical noteFunding Information:
Support is acknowledged from the 2020 Sapienza Large Project: Dynamics of Biological and Artificial Lipid Bilayer Membranes. Concerning computational resources, we acknowledge PRACE for awarding us access to Marconi’s successor at CINECA, Italy, PRACE 23rd call project No. 2021240074; DECI 17 SOLID project for resource Navigator based in Portugal at https://www.uc.pt/lca/ from the PRACE aisbl; CINECA award under the ISCRA initiative, for the availability of high-performance computing resources and support (ISCRA-B FHDAS, ISCRA-C ToTraVes).
© 2022, The Author(s).
- Membrane biophysics
- Biological physics