Influence of TMAO and urea on the structure of water studied by inelastic X-ray scattering. Issue 24 (7th June 2016)

• Record Type: Journal Article
• Authors: Sahle, Christoph J.; Schroer, Martin A.; Juurinen, Iina; Niskanen, Johannes
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 24(2016)
• Page Start: 16518
• Page End: 16526
• Publication Date: 2016-06-07
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp01922f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We present a study on the influence of the naturally occurring organic osmolytes tri-methylamine N -oxide (TMAO) and urea on the bulk structure of water using X-ray Raman scattering spectroscopy. Abstract : We present a study on the influence of the naturally occurring organic osmolytes tri-methylamine N -oxide (TMAO) and urea on the bulk structure of water using X-ray Raman scattering spectroscopy. Addition of TMAO is known to stabilize proteins in otherwise destabilizing aqueous urea solutions. The experimental X-ray Raman scattering spectra change systematically with increasing solute concentration revealing different effects on the structure of water due to the presence of the two osmolytes. Although these effects are distinct for both molecular species, they have mutually compensating influences on the spectra of the ternary water–TMAO–urea mixtures. This compensation effect seen in the spectra vanishes only at the highest studied ternary concentration of 4 M : 4 M (TMAO : urea). Our experiment shows that the hydrogen-bonding structure of water remains rather intact in the presence of the aforementioned osmolytes if both of them are present.