Hydrophobic interactions in presence of osmolytes urea and trimethylamine-N-oxide

Rahul Sarma, Sandip Paul

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Molecular dynamics simulations were carried out to study the influences of two naturally occurring osmolytes, urea, and trimethylamine-N-oxide (TMAO) on the hydrophobic interactions between neopentane molecules. In this study, we used two different models of neopentane: One is of single united site (UA) and another contains five-sites. We observe that, these two neopentane models behave differently in pure water as well as solutions containing osmolytes. Presence of urea molecules increases the stability of solvent-separated state for five-site model, whereas osmolytes have negligible effect in regard to clustering of UA model of neopentane. For both models, dehydration of neopentane and preferential solvation of it by urea and TMAO over water molecules are also observed. We also find the collapse of the second-shell of water by urea and water structure enhancement by TMAO. The orientational distributions of water molecules around different layers of neopentane were also calculated and we find that orientation of water molecules near to hydrophobic moiety is anisotropic and osmolytes have negligible effect on it. We also observe osmolyte-induced water-water hydrogen bond life time increase in the hydration shell of neopentane as well as in the subsequent water layers.

Original languageEnglish (US)
Article number174501
JournalJournal of Chemical Physics
Volume135
Issue number17
DOIs
StatePublished - Nov 7 2011
Externally publishedYes

Fingerprint

neopentane
ureas
Urea
oxides
Water
water
interactions
Molecules
molecules
trimethyloxamine
Solvation
Dehydration
dehydration
Hydration
solvation
hydration
Molecular dynamics
Hydrogen bonds
hydrogen bonds
molecular dynamics

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Hydrophobic interactions in presence of osmolytes urea and trimethylamine-N-oxide. / Sarma, Rahul; Paul, Sandip.

In: Journal of Chemical Physics, Vol. 135, No. 17, 174501, 07.11.2011.

Research output: Contribution to journalArticle

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