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Updated: Jun 6, 2026
High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water
Published on: April 28, 2022
Temperature- and hydration-dependent internal dynamics of stripped human erythrocyte vesicles studied by incoherent
S Combet1, J-M Zanotti, M-C Bellissent-Funel
1Laboratoire Léon-Brillouin, UMR 12 CEA/CNRS, Gif-sur-Yvette Cedex, France. spohie.combet@cea.fr
Background:
We focus on temperature- and hydration-dependence of internal molecular motions in stripped human red blood cell (RBC) vesicles, widely used as a model system for more complex biomembranes.
Methods:
We singled out picosecond local motions of the non-exchangeable hydrogen atoms of RBC vesicles by performing elastic and quasielastic incoherent neutron scattering measurements in dry and heavy water (D₂O)-hydrated RBC powders.
Results:
In dry stripped RBCs, hydrogen motions remained harmonic all along the measured temperature range (100-310K) and mean-square displacements (MSDs) exhibited no temperature transition up to 310K. In contrast, MSDs of hydrated stripped RBCs (h ≈ 0.38g D₂O/g dry powder) exhibited a pronounced transition near 260K, with the sharp rise of anharmonic diffusive motions of hydrogen atoms. This transition at ~260K was correlated with both the onset of nonvibrational (harmonic and nonharmonic) motions and the melting of crystallized hydration water.
General Significance:
In conclusion, we have shown that MSDs in human RBC vesicles are temperature-and hydration-dependent. These results provide insight into biomembrane internal dynamics at picosecond timescale and nanometer length scale. Such motions have been shown to act as the "lubricant" of larger conformational changes on a slower, millisecond timescale that are necessary for important biological processes.
