Abstract
We experimentally investigate the effect of lipid charge on the stiffness of bilayer membranes. The bending rigidity of membranes with composition 0-100 mol% of charged lipids, in the absence and presence of salt at different concentrations, is measured with the flicker spectroscopy method, using the shape fluctuations of giant unilamellar vesicles. The analysis considers both the mean squared amplitudes and the time autocorrelations of the shape modes. Our results show that membrane charge increases the bending rigidity relative to the charge-free membrane. The effect is diminished by the addition of monovalent salt to the suspending solutions. The trend shown by the membrane bending rigidity correlates with zeta potential measurements, confirming charge screening at different salt concentrations. The experimental results in the presence of salt are in good agreement with existing theories of membrane stiffening by surface charge.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6006-6013 |
| Number of pages | 8 |
| Journal | Soft Matter |
| Volume | 15 |
| Issue number | 29 |
| DOIs | |
| State | Published - 2019 |
Funding
This research was funded in part by NSF-CMMI awards 1748049 and 1740011. PV acknowledges support from the Alexander von Humboldt Foundation for a visit to the Max Planck Institute of Colloids and Interfaces. JS and RD acknowledge the stimulating environment of the MaxSynBio consortium which is jointly funded by the Federal Ministry of Education and Research in Germany and the Max Planck Society. Open Access funding provided by the Max Planck Society.
ASJC Scopus subject areas
- General Chemistry
- Condensed Matter Physics