Membrane water-penetration profiles from spin labels
Related Experiment Video
Updated: Sep 27, 2026

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification
Published on: April 7, 2017
1Max-Planck-Institut für biophysikalische Chemie, Abteilung Spektroscopie, 37070 Göttingen, Germany. dmarsh@gwdg.de
Abstract:
Spin label hyperfine splittings in mixtures of protic and aprotic solvents are used to obtain association constants K(A,h) for hydrogen bonding to oxazolidine nitroxides. With the Onsager approach to account for the variation in local dielectric constant, these results are used to determine the effective penetration profile of water into fluid phospholipid membranes, from recent electron paramagnetic resonance (EPR) studies on phospholipids spin-labelled systematically down the sn-2 chain. Water penetration is appreciable, depends on chain unsaturation, and is strongly affected by cholesterol.
Related Concept Videos
Membrane Fluidity
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...

