Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/176805
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Investigation of the dynamics of aqueous proline solutions using neutron scattering and molecular dynamics simulations |
Autor: | Malo de Molina, Paula CSIC ORCID; Álvarez González, Fernando CSIC ORCID; Frick, Bernhard; Wildes, Andrew; Arbe, Arantxa CSIC ORCID; Colmenero de León, Juan CSIC ORCID | Fecha de publicación: | 2017 | Editor: | Royal Society of Chemistry (UK) | Citación: | Physical Chemistry Chemical Physics 19(40): 27739-27754 (2017) | Resumen: | We applied quasielastic neutron scattering (QENS) techniques to samples with two different contrasts (deuterated solute/hydrogenated solvent and the opposite label) to selectively study the component dynamics of proline/water solutions. Results on diluted and concentrated solutions (31 and 6 water molecules/proline molecule, respectively) were analyzed in terms of the susceptibility and considering a recently proposed model for water dynamics [Arbe et al., Phys. Rev. Lett., 2016, 117, 185501] which includes vibrations and the convolution of localized motions and diffusion. We found that proline molecules not only reduce the average diffusion coefficient of water but also extend the time/frequency range of the crossover region (‘cage’) between the vibrations and purely diffusive behavior. For the high proline concentration we also found experimental evidence of water heterogeneous dynamics and a distribution of diffusion coefficients. Complementary molecular dynamics simulations show that water molecules start to perform rotational diffusion when they escape the cage regime but before the purely diffusive behavior is established. The rotational diffusion regime is also retarded by the presence of proline molecules. On the other hand, a strong coupling between proline and water diffusive dynamics which persists with decreasing temperature is directly observed using QENS. Not only are the temperature dependences of the diffusion coefficients of both components the same, but their absolute values also approach each other with increasing proline concentration. We compared our results with those reported using other techniques, in particular using dielectric spectroscopy (DS). A simple approach based on molecular hydrodynamics and a molecular treatment of DS allows rationalizing the a priori puzzling inconsistency between QENS and dielectric results regarding the dynamic coupling of the two components. The interpretation proposed is based on general grounds and therefore should be applicable to other biomolecular solutions. | URI: | http://hdl.handle.net/10261/176805 | DOI: | 10.1039/C7CP05474B | Identificadores: | doi: 10.1039/C7CP05474B issn: 1463-9076 e-issn: 1463-9084 |
Aparece en las colecciones: | (CFM) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
accesoRestringido.pdf | 15,38 kB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
WEB OF SCIENCETM
Citations
10
checked on 22-feb-2024
Page view(s)
136
checked on 24-abr-2024
Download(s)
38
checked on 24-abr-2024
Google ScholarTM
Check
Altmetric
Altmetric
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.