Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 39, 2016
Previous Article Next Article

Fast and slow dynamics and the local structure of liquid and supercooled water next to a hydrophobic amino acid

Author affiliations

Abstract

We study, through molecular dynamics simulations, the structure and orientational dynamics of water next to a blocked hydrophobic amino acid, valine (Val), above and below the freezing point of water. The structure and the orientational dynamics of waters with four water neighbors (4WN) and less than four water neighbors (L4WN) in the Val's coordination sphere are deconvoluted. We find that in spite of the excluded volume effects waters with L4WN have faster librational dynamics than bulk water, reminiscent of water at the liquid–vapor interface, and faster orientational dynamics than waters with 4WN, at every temperature. Furthermore, our results show that the pronounced decrease of the orientational retardation factor below ∼255 K observed experimentally is mostly caused by the acceleration of the orientational dynamics of waters with L4WN, while waters with 4WN exhibit only moderate acceleration. The differences between the hydrogen-bond acceptor switching mechanism in the shell and the bulk are also analyzed, and no evidence of especially slow OH groups neither in the 4WN nor in the L4WN populations is found. Finally, we show that waters with 4WN have higher tetrahedrality than bulk water at every temperature although this difference decreases at both high and low temperatures.

Graphical abstract: Fast and slow dynamics and the local structure of liquid and supercooled water next to a hydrophobic amino acid

Back to tab navigation

Supplementary files

Article information


Submitted
28 Jun 2016
Accepted
06 Sep 2016
First published
07 Sep 2016

Phys. Chem. Chem. Phys., 2016,18, 27639-27647
Article type
Paper

Fast and slow dynamics and the local structure of liquid and supercooled water next to a hydrophobic amino acid

H. F. M. C. Martiniano and N. Galamba, Phys. Chem. Chem. Phys., 2016, 18, 27639
DOI: 10.1039/C6CP04532D

Social activity

Search articles by author

Spotlight

Advertisements