Abstract
Temperature-dependent onset of apparent anharmonicity in the microscopic dynamics of hydrated proteins and other biomolecules has been known as protein dynamical transition for the last quarter of a century. Using neutron scattering and molecular dynamics simulation, techniques most often associated with protein dynamical transition studies, we have investigated the microscopic dynamics of one of the most common polymers, polystyrene, which was exposed to toluene vapor, mimicking the process of protein hydration from water vapor. Polystyrene with adsorbed toluene is an example of a solvent-solute system, which, unlike biopolymers, is anhydrous and lacks hydrogen bonding. Nevertheless, it exhibits the essential traits of the dynamical transition in biomolecules, such as a specific dependence of the microscopic dynamics of both solvent and host on the temperature and the amount of solvent adsorbed. We conclude that the protein dynamical transition is a manifestation of a universal solvent-solute dynamical relationship, which is not specific to either biomolecules as solute, or aqueous media as solvent, or even a particular type of interactions between solvent and solute. (Graph Presented).
| Original language | English |
|---|---|
| Pages (from-to) | 3232-3239 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry B |
| Volume | 120 |
| Issue number | 12 |
| DOIs | |
| State | Published - Mar 31 2016 |
Funding
The neutron scattering experiments on HFBS at NCNR were supported in part by the National Science Foundation under Agreement No. DMR-1508249. The neutron scattering experiments on BASIS at SNS were supported by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. J.M.B. is supported by the Center for Accelerating Materials Modeling (CAMM) funded by the U.S. Department of Energy, Basic Energy Sciences, Material Sciences and Engineering Division under FWP-3ERKCSNL. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paidup, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). Certain commercial material suppliers are identified in this paper to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose. The authors declare no competing financial interests.
| Funders | Funder number |
|---|---|
| Center for Accelerating Materials Modeling | |
| DOE Public Access Plan | |
| Scientific User Facilities Division | |
| United States Government | |
| National Science Foundation | DMR-1508249 |
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| Basic Energy Sciences | DE-AC05-00OR22725, FWP-3ERKCSNL |