Motions of water and solutes-Slaving versus plasticization phenomena
Journal article, 2019

It is well-accepted that hydration water is crucial for the structure, dynamics, and function of proteins. However, the exact role of water for the motions and functions of proteins is still debated. Experiments have shown that protein and water dynamics are strongly coupled but with water motions occurring on a considerably faster time scale (the so-called slaving behavior). On the other hand, water also reduces the conformational entropy of proteins and thereby acts as a plasticizer of them. In this work, we analyze the dynamics (using broadband dielectric spectroscopy) of some specific non-biological water solutions in a broad concentration range to elucidate the role of water in the dynamics of the solutes. Our results demonstrate that at low water concentrations (less than 5 wt. %), the plasticization phenomenon prevails for all the materials analyzed. However, at higher water concentrations, two different scenarios can be observed: the slaving phenomenon or plasticization, depending on the solute analyzed. These results generalize the slaving phenomenon to some, but not all, non-biological solutions and allow us to analyze the key factors for observing the slaving behavior in protein solutions as well as to reshaping the slaving concept.

Author

Izaskun Combarro Palacios

University of the Basque Country (UPV/EHU)

Christoffer Olsson

Chalmers, Physics, Biological Physics

Christina S. Kamma-Lorger

ALBA Synchrotron Light Facility

Jan Swenson

Chalmers, Physics, Biological Physics

Silvina Cerveni

University of the Basque Country (UPV/EHU)

Donostia International Physics Center

Journal of Chemical Physics

0021-9606 (ISSN) 1089-7690 (eISSN)

Vol. 150 12 124902

Structure and dynamics of soft and biological materials. I & II

Swedish Research Council (VR), 2016-01-01 -- 2019-12-31.

Swedish Research Council (VR), 2012-01-01 -- 2015-12-31.

Subject Categories

Physical Chemistry

Biophysics

Oceanography, Hydrology, Water Resources

DOI

10.1063/1.5030064

PubMed

30927900

More information

Latest update

7/11/2019