Elliptical <scp> <i>β</i> </scp> ‐barrel deformation underlies gating in <scp>VDAC1</scp>
Gating by voltage-dependent anion channels (VDAC) regulates mitochondrial metabolite flux, yet the structural mechanism underlying the open-to-closed transition remains unresolved. Here, we combine atomistic molecular dynamics (MD) simulations with double electron-electron resonance (DEER), using hydrostatic pressure as a reversible thermodynamic perturbation to shift conformational equilibria and stabilize low-population states. MD simulations reveal localized intrinsic flexibility within β-strands β1-β5 and β19, as well as in cytosolic loops connecting β6-β7 and β8-β9. High-pressure DEER measurements in lipid nanodiscs corroborate these predictions, identifying reversible, pressure-dependent distance changes within the pore lumen consistent with asymmetric deformation of the β-barrel. DEER-informed analysis of unbiased MD trajectories reveals an elliptical β-barrel conformation aligned parallel to the N-terminal helix that corresponds to the pressure-stabilized experimental state. ATP permeation simulations identify a free-energy barrier to metabolite translocation in this elliptical geometry, whereas diffusion through the circular open state is energetically favorable. These findings indicate that the elliptical conformation represents a transient gating-competent state rather than a fully closed channel. Together, our results support a gating mechanism driven by reversible β-barrel deformation and establish pressure-perturbed DEER integrated with MD as a general strategy for capturing transient, functionally relevant conformations of membrane channels.
Authors
- Matthias Elgeti (ORCID: https://orcid.org/0000-0002-0550-4852)
- Jeff Abramson (ORCID: https://orcid.org/0000-0003-0004-7426)
- Lucie Bergdoll (ORCID: https://orcid.org/0000-0001-6068-238X)
- Alexander Zlobin (ORCID: https://orcid.org/0000-0001-8627-0455)
- W. Hubbell
- J. P. Duneau
- J. Belyaeva
Institutions
- Centre National de la Recherche Scientifique (FR)
- University of California, Los Angeles (US)
- Doheny Eye Institute (US)
- Laboratoire d’Informatique et Systèmes (FR)
- Leipzig University (DE)
Publication Details
- Journal
- Protein Science
- Published
- 2026-06-19
- DOI
- https://doi.org/10.1002/pro.70677
- Primary Topic
- Mitochondrial Function and Pathology
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Grand Équipement National De Calcul Intensif
- National Institutes of Health