Abstract
A new investigation of the structure of urea-water solutions at a mole ratio of 1 urea to 4 water molecules is described. Neutron diffraction is used in conjunction with isotope labelling on the water and urea hydrogen atoms and on the nitrogen atom of urea. The diffraction data are analysed using the empirical potential structure refinement procedure to yield a set of site-site radial distribution functions and spatial density functions that are consistent with the diffraction data. The results are discussed in relation to recent and past X-ray and neutron diffraction experiments and theoretical studies of this system. It is found that urea incorporates readily into water, forming pronounced hydrogen bonds with water at both the amine and carbonyl headgroups. In addition the urea also hydrogen bonds to itself, forming chains or clusters consisting of up to approximately 60 urea molecules in a cluster. There, is however, little or no evidence of urea segregating itself from water, in marked contrast to a recent study of the methanol-water system. This behaviour is discussed in the context of the great propensity of urea to effect protein denaturation.
| Original language | English |
|---|---|
| Pages (from-to) | 649-666 |
| Number of pages | 18 |
| Journal | Biophysical Chemistry |
| Volume | 105 |
| Issue number | 2-3 |
| DOIs | |
| Publication status | Published - Sep 1 2003 |
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Keywords
- Hydration
- Isotope substitution
- Neutron diffraction
- Protein denaturation
ASJC Scopus subject areas
- Biochemistry
- Physical and Theoretical Chemistry
- Biophysics
Cite this
Impact of urea on water structure : A clue to its properties as a denaturant? / Soper, A. K.; Castner, Ed; Luzar, Alenka.
In: Biophysical Chemistry, Vol. 105, No. 2-3, 01.09.2003, p. 649-666.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Impact of urea on water structure
T2 - A clue to its properties as a denaturant?
AU - Soper, A. K.
AU - Castner, Ed
AU - Luzar, Alenka
PY - 2003/9/1
Y1 - 2003/9/1
N2 - A new investigation of the structure of urea-water solutions at a mole ratio of 1 urea to 4 water molecules is described. Neutron diffraction is used in conjunction with isotope labelling on the water and urea hydrogen atoms and on the nitrogen atom of urea. The diffraction data are analysed using the empirical potential structure refinement procedure to yield a set of site-site radial distribution functions and spatial density functions that are consistent with the diffraction data. The results are discussed in relation to recent and past X-ray and neutron diffraction experiments and theoretical studies of this system. It is found that urea incorporates readily into water, forming pronounced hydrogen bonds with water at both the amine and carbonyl headgroups. In addition the urea also hydrogen bonds to itself, forming chains or clusters consisting of up to approximately 60 urea molecules in a cluster. There, is however, little or no evidence of urea segregating itself from water, in marked contrast to a recent study of the methanol-water system. This behaviour is discussed in the context of the great propensity of urea to effect protein denaturation.
AB - A new investigation of the structure of urea-water solutions at a mole ratio of 1 urea to 4 water molecules is described. Neutron diffraction is used in conjunction with isotope labelling on the water and urea hydrogen atoms and on the nitrogen atom of urea. The diffraction data are analysed using the empirical potential structure refinement procedure to yield a set of site-site radial distribution functions and spatial density functions that are consistent with the diffraction data. The results are discussed in relation to recent and past X-ray and neutron diffraction experiments and theoretical studies of this system. It is found that urea incorporates readily into water, forming pronounced hydrogen bonds with water at both the amine and carbonyl headgroups. In addition the urea also hydrogen bonds to itself, forming chains or clusters consisting of up to approximately 60 urea molecules in a cluster. There, is however, little or no evidence of urea segregating itself from water, in marked contrast to a recent study of the methanol-water system. This behaviour is discussed in the context of the great propensity of urea to effect protein denaturation.
KW - Hydration
KW - Isotope substitution
KW - Neutron diffraction
KW - Protein denaturation
UR - http://www.scopus.com/inward/record.url?scp=0141560450&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0141560450&partnerID=8YFLogxK
U2 - 10.1016/S0301-4622(03)00095-4
DO - 10.1016/S0301-4622(03)00095-4
M3 - Article
VL - 105
SP - 649
EP - 666
JO - Biophysical Chemistry
JF - Biophysical Chemistry
SN - 0301-4622
IS - 2-3
ER -