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Changes in water structure induced by the guanidinium cation and implications for protein denaturation.

ABSTRACT: The effect of the guanidinium cation on the hydrogen bonding strength of water was analyzed using temperature-excursion Fourier transform infrared spectra of the OH stretching vibration in 5% H 2O/95% D 2O solutions containing a range of different guanidine-HCl and guanidine-HBr concentrations. Our findings indicate that the guanidinium cation causes the water H-bonds in solution to become more linear than those found in bulk water, and that it also inhibits the response of the H-bond network to increased temperature. Quantum chemical calculations also reveal that guanidinium affects both the charge distribution on water molecules directly H-bonded to it as well as the OH stretch frequency of H-bonds in which that water molecule is the donor. The implications of our findings to hydrophobic solvation and protein denaturation are discussed.

SUBMITTER: Scott JN

PROVIDER: S-EPMC2646201 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature

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Changes in water structure induced by the guanidinium cation and implications for protein denaturation.

Scott J Nathan JN Nucci Nathaniel V NV Vanderkooi Jane M JM

The journal of physical chemistry. A 20081008 43

The effect of the guanidinium cation on the hydrogen bonding strength of water was analyzed using temperature-excursion Fourier transform infrared spectra of the OH stretching vibration in 5% H 2O/95% D 2O solutions containing a range of different guanidine-HCl and guanidine-HBr concentrations. Our findings indicate that the guanidinium cation causes the water H-bonds in solution to become more linear than those found in bulk water, and that it also inhibits the response of the H-bond network to ...[more]

PMID: 18839935

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