Molugu, TR and Xu, X and Lee, S and Mallikarjunaiah, KJ and Brown, MF (2018) Solid-state 2 H NMR studies of water- mediated lipid membrane deformation. [Book Chapter]
Full text not available from this repository.Abstract
The application of solid-state 2 H nuclear magnetic resonance (NMR) spectroscopy gives a powerful approach for investigating hydration-mediated effects on lipid bilayer structure and dynamics. The extent to which lipid bilayers are deformed by dehydration stress is inherent to understanding how lipid-protein interactions affect biomembrane functioning. For liquid-crystalline membranes, the average structure is manifested by the segmental order parameters (S CD ) of the lipids. Structural quantities, such as the area per lipid and volumetric bilayer thickness, are obtained by a mean-torque analysis of 2 H NMR order parameters. Removal of water in the liquid-crystalline state gives a reduction of the mean area per lipid, together with a corresponding increase in volumetric bilayer thickness. Measurements of order parameters versus osmotic pressure yield the elastic area compressibility modulus and the corresponding bilayer thickness at an atomistic level. Furthermore, solid-state 2 H NMR relaxation rates of lipid bilayers at varying hydration levels afford new insights into the role of water in membrane structural dynamics and viscoelastic properties. Model-free interpretation of spinlattice (R 1Z ) and transverse (R QE 2 ) relaxation rates suggests that collective chain motions described as order-director fluctuations dominantly contribute to the relaxation. In a continuum picture, elastic deformations in such materials are collective hydrodynamic phenomena with motional time scales spanning many decades (picoseconds to seconds). The dynamic processes mainly affecting the spin-spin relaxation have characteristic time scales much longer than those contributing to spin-lattice relaxation. Such studies probe membrane interactions involving collective bilayer undulations, order-director fluctuations, and lipid molecular protrusions, giving a unique source of information about intermolecular forces pertinent to biomembrane structure and function.
| Item Type: | Book Chapter |
|---|---|
| Publication: | Modern Magnetic Resonance |
| Publisher: | Springer International Publishing |
| Additional Information: | The copyright for this article belongs to the Springer International Publishing. |
| Keywords: | Chemical bonds; Deformation; Hydration; Lipids; Liquid crystals; Molecular dynamics; Nuclear magnetic resonance spectroscopy; Osmosis; Structural dynamics; Viscoelasticity, Lipid-protein interactions; Liquid crystalline membranes; Liquid crystalline state; NMR relaxation; Nuclear magnetic resonance(NMR); Order director fluctuation; Osmotic stress; Viscoelastic properties, Lipid bilayers |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 11 Aug 2022 09:51 |
| Last Modified: | 11 Aug 2022 09:51 |
| URI: | https://eprints.iisc.ac.in/id/eprint/75511 |
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