This title appears in the Scientific Report :
2020
Please use the identifier:
http://hdl.handle.net/2128/25342 in citations.
Please use the identifier: http://dx.doi.org/10.1063/5.0011107 in citations.
Quasielastic neutron scattering studies on couplings of protein and water dynamics in hydrated elastin
Quasielastic neutron scattering studies on couplings of protein and water dynamics in hydrated elastin
erforming quasielastic neutron scattering measurements and analyzing both elastic and quasielasic contributions, we study protein and water dynamics of hydrated elastin. At low temperatures, hydration-independent methyl group rotation dominates the findings. It is characterized by a Gaussian distrib...
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Personal Name(s): | Kämpf, Kerstin |
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Demuth, Dominik / Zamponi, Michaela / Wuttke, Joachim / Vogel, Michael (Corresponding author) | |
Contributing Institute: |
Neutronenstreuung; JCNS-1 Heinz Maier-Leibnitz Zentrum; MLZ JCNS-FRM-II; JCNS-FRM-II |
Published in: | The journal of chemical physics, 152 (2020) 24, S. 245101 - |
Imprint: |
Melville, NY
American Institute of Physics
2020
|
PubMed ID: |
32610976 |
DOI: |
10.1063/5.0011107 |
Document Type: |
Journal Article |
Research Program: |
Jülich Centre for Neutron Research (JCNS) FRM II / MLZ |
Subject (ZB): | |
Link: |
Published on 2020-06-30. Available in OpenAccess from 2021-06-30. Published on 2020-06-30. Available in OpenAccess from 2021-06-30. |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1063/5.0011107 in citations.
erforming quasielastic neutron scattering measurements and analyzing both elastic and quasielasic contributions, we study protein and water dynamics of hydrated elastin. At low temperatures, hydration-independent methyl group rotation dominates the findings. It is characterized by a Gaussian distribution of activation energies centered at about Em = 0.17 eV. At ∼195 K, coupled protein–water motion sets in. The hydration water shows diffusive motion, which is described by a Gaussian distribution of activation energies with Em = 0.57 eV. This Arrhenius behavior of water diffusion is consistent with previous results for water reorientation, but at variance with a fragile-to-strong crossover at ∼225 K. The hydration-related elastin backbone motion is localized and can be attributed to the cage rattling motion. We speculate that its onset at ∼195 K is related to a secondary glass transition, which occurs when a β relaxation of the protein has a correlation time of τβ ∼ 100 s. Moreover, we show that its temperature-dependent amplitude has a crossover at the regular glass transition Tg = 320 K of hydrated elastin, where the α relaxation of the protein obeys τα ∼ 100 s. By contrast, we do not observe a protein dynamical transition when water dynamics enters the experimental time window at ∼240 K. |