Identifying chaotropic and kosmotropic agents by nanorheology
Author
dc.contributor.author
Casanova Morales, Nathalie
Author
dc.contributor.author
Alavi, A.
Author
dc.contributor.author
Wilson, Christian A.M.
Author
dc.contributor.author
Zocchi, Giovanni
Admission date
dc.date.accessioned
2018-08-27T19:28:32Z
Available date
dc.date.available
2018-08-27T19:28:32Z
Publication date
dc.date.issued
2018
Cita de ítem
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Journal of Physical Chemistry B Volumen: 122 Número: 14 Páginas: 3754-3759
es_ES
Identifier
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10.1021/acs.jpcb.7b12782
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/151300
Abstract
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Chemical agents are classified into chaotropes (disorder inducing) and kosmotropes (order inducing) based on their ability to destabilize or stabilize, respectively, the structure of hydrated macromolecules and their solutions. Here, we examine the effect of such agents on the mechanical stiffness of the hydration layer of proteins, measured by nanorheology. We examine four different agents and conclude that chaotropic substances induce the overall softening of the protein-hydration layer system, whereas the kosmotropic substances induce stiffening. Specifically, with glucose and trifluoroethanol, two known kosmotropic agents, we observe the stiffening of the hydration layer. In contrast, with guanidine hydrochloride and urea, known kaotropic agents, we observe softening. Thus, the viscoelastic mechanics of the folded, hydrated protein provides an experimental measure of the effect that chaotropes and kosmotropes have on the dynamics.