Related Experiment Videos
Structural determinants of MscL gating studied by molecular dynamics simulations
J Gullingsrud1, D Kosztin, K Schulten
1Beckman Institute, Department of Physics, University of Illinois, 405 N. Mathews Avenue, Urbana, Illinois 61801, USA.
Biophysical Journal
|April 28, 2001
Summary
The mechanosensitive channel of large conductance (MscL) remains closed in simulations, showing least mobility at its narrowest point. Applying tension causes its transmembrane helices to flatten, widening the pore.
Area of Science:
- Biophysics
- Molecular Biology
- Computational Biology
Background:
- Mechanosensitive channel of large conductance (MscL) is vital for prokaryotic cell survival.
- MscL responds to membrane tension and osmotic stress, regulating cell volume.
- Previous studies identified key residues and determined MscL crystal structure.
Purpose of the Study:
- To investigate the gating mechanism of MscL using molecular dynamics simulations.
- To understand the protein's behavior within a lipid bilayer under tension.
Main Methods:
- Molecular dynamics simulations of MscL in a POPC bilayer.
- Simulations conducted under constant temperature and pressure with full electrostatics.
- Analysis of protein fluctuations and response to applied surface tension.
Main Results:
- MscL remained in a closed, water-impermeable state consistent with crystal structure.
- Least protein mobility observed at the narrowest region of the MscL channel.
- Simulations under tension showed transmembrane helices flattening as the pore widened.
Conclusions:
- The study provides insights into MscL gating dynamics at a molecular level.
- Flattening of transmembrane helices is implicated in MscL pore opening.
- Computational findings complement experimental data on MscL function.