Abstract
Fast stochastic equilibrium fluctuations (time scale: 10–10–10–13 seconds) in purple membranes (PM) and in disk membranes (DM) have been measured with quasielastic incoherent neutron scattering. The comparison of predominantly stochastic motions occurring in purple membranes and in disk membranes revealed qualitatively similar dynamical behaviour. Models of internal motions within restricted volumes have been shown to be useful to fit the spectra from both samples. From fits using these models we found “amplitudes” 15 to 20% larger for motions in DM samples compared to PM samples. This indicates a higher internal flexibility of the DM. Because the dynamical behaviour is very sensitive to the hydration of the protein-lipid complex, we also performed neutron diffraction experiments to determine lamellar spacings as a measure of level of hydration and as a function of temperature. From these studies the interaction of solvent molecules with the surface of the protein-lipid complex appears to be qualitatively similar for both types of membranes.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 12 February 1998 / Revised version: 18 March 1998 / Accepted: 27 March 1998
Rights and permissions
About this article
Cite this article
Fitter, J., Ernst, O., Hauß, T. et al. Molecular motions and hydration of purple membranes and disk membranes studied by neutron scattering. Eur Biophys J 27, 638–645 (1998). https://doi.org/10.1007/s002490050175
Issue Date:
DOI: https://doi.org/10.1007/s002490050175