Gibbs energies, enthalpies, and entropies of water and lysozyme at the inner edge of excess hydration

Sirotkin, Vladimir A.; Khadiullina, Aigul V.

doi:10.1063/1.4818527

Cited by 14 publications

(21 citation statements)

References 53 publications

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“… (A) The preferential solvation parameters as a function of water mass fraction in acetone (

{(\partial g_{3} / \partial g_{2})}_{T, μ 1, μ 3}

): 1—Dried α‐chymotrypsin; 2—Hydrated α‐chymotrypsin. (B) Gibbs energy of the transfer of water (

{Δ G}_{1}^{p r e f}

) from binary water–organic mixtures to the solvation shell: 1—Dried α‐chymotrypsin; 2—Hydrated α‐chymotrypsin; 3—Excess Gibbs energy of water bound to the dried protein . Reference state is pure liquid water at 25°C [Color figure can be viewed at http://wileyonlinelibrary.com]…”

Section: Resultsmentioning

confidence: 99%

“…The

{Δ G}_{1}^{p r e f}

value at w 1 = 0 (Figure ) was compared with the excess Gibbs energy of water bound to the dried protein . This Gibbs energy was determined from the water sorption experiments without acetone.…”

Section: Resultsmentioning

confidence: 99%

“…The DG pref 1 value at w 1 5 0 ( Figure 9) was compared with the excess Gibbs energy of water bound to the dried protein. 38 This Gibbs energy was determined from the water sorption experiments without acetone. Strong agreement between our data and previously published results was observed, as shown in Figure 9.…”

Section: Equation 12mentioning

confidence: 99%

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α-chymotrypsin in water-acetone and water-dimethyl sulfoxide mixtures: Effect of preferential solvation and hydration

Sirotkin

Kuchierskaya

2017

Proteins

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We investigated water/organic solvent sorption and residual enzyme activity to simultaneously monitor preferential solvation/hydration of protein macromolecules in the entire range of water content at 25°C. We applied this approach to estimate protein destabilization/stabilization due to the preferential interactions of bovine pancreatic α-chymotrypsin with water-acetone (moderate-strength H-bond acceptor) and water-DMSO (strong H-bond acceptor) mixtures. There are three concentration regimes for the dried α-chymotrypsin. α-Chymotrypsin is preferentially hydrated at high water content. The residual enzyme activity values are close to 100%. At intermediate water content, the dehydrated α-chymotrypsin has a higher affinity for acetone/DMSO than for water. Residual enzyme activity is minimal in this concentration range. The acetone/DMSO molecules are preferentially excluded from the protein surface at the lowest water content, resulting in preferential hydration. The residual catalytic activity in the water-poor acetone is ∼80%, compared with that observed after incubation in pure water. This effect is very small for the water-poor DMSO. Two different schemes are operative for the hydrated enzyme. At high and intermediate water content, α-chymotrypsin exhibits preferential hydration. However, at intermediate water content, in contrast to the dried enzyme, the initially hydrated α-chymotrypsin possesses increased preferential hydration parameters. At low water content, no residual enzyme activity was observed. Preferential binding of DMSO/acetone to α-chymotrypsin was detected. Our data clearly demonstrate that the hydrogen bond accepting ability of organic solvents and the protein hydration level constitute key factors in determining the stability of protein-water-organic solvent systems.

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“… (A) The preferential solvation parameters as a function of water mass fraction in acetone (

{(\partial g_{3} / \partial g_{2})}_{T, μ 1, μ 3}

): 1—Dried α‐chymotrypsin; 2—Hydrated α‐chymotrypsin. (B) Gibbs energy of the transfer of water (

{Δ G}_{1}^{p r e f}

Section: Resultsmentioning

confidence: 99%

“…The

{Δ G}_{1}^{p r e f}

value at w 1 = 0 (Figure ) was compared with the excess Gibbs energy of water bound to the dried protein . This Gibbs energy was determined from the water sorption experiments without acetone.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

α-chymotrypsin in water-acetone and water-dimethyl sulfoxide mixtures: Effect of preferential solvation and hydration

Sirotkin

Kuchierskaya

2017

Proteins

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“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Computational simulations provide a detailed understanding of water properties at a molecular level that would otherwise require expensive experimental equipment to access. The calculations of enthalpy, entropy, and free energy of water from molecular simulations also provide insight into the stability of water near proteins 15,16 and nanomaterials, 17 and the phase behavior of gas hydrates.…”

Section: Introductionmentioning

confidence: 99%

Diffusive and quantum effects of water properties in different states of matter

Yeh

Huang

Chen

et al. 2014

The Journal of Chemical Physics

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The enthalpy, entropy, and free energy of water are important physical quantities for understanding many interesting phenomena in biological systems. However, conventional approaches require different treatments to incorporate quantum and diffusive effects of water in different states of matter. In this work, we demonstrate the use of the two-phase thermodynamic (2PT) model as a unified approach to obtain the properties of water over the whole phase region of water from short (∼20 ps) classical molecular dynamics trajectories. The 2PT model provides an effective way to separate the diffusive modes (gas-like component) from the harmonic vibrational modes (solid-like component) in the vibrational density of states (DoS). Therefore, both diffusive and quantum effect can be properly accounted for water by applying suitable statistical mechanical weighting functions to the DoS components. We applied the 2PT model to systematically examine the enthalpy, entropy, and their temperature dependence of five commonly used rigid water models. The 2PT results are found to be consistent with those obtained from more sophisticated calculations. While the thermodynamic properties determined from different water models are largely similar, the phase boundary determined from the equality of free energy is very sensitive to the small inaccuracy in the values of enthalpy and absolute entropy. The enthalpy, entropy, and diffusivity of water are strongly interrelated, which challenge further improvement of rigid water model via parameter fitting. Our results show that the 2PT is an efficient method for studying the properties of water under various chemical and biological environments.

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“…6,7) Subsequent works analyzed the water sorption behavior of moistened food in the region of high water content by regarding it as solution. [8][9][10][11] From a thermodynamic equation shown later in this report, DG s a is taken to be the contribution of "change in state of solid" to the change in Gibbs free energy ΔG s . According to the reports of Kumagai et al, [5][6][7] DG s a greatly contributed to ΔG s at high water content, probably due to changes in the solid material.…”

mentioning

confidence: 99%

Analysis of water sorption isotherms of amorphous food materials by solution thermodynamics with relevance to glass transition: evaluation of plasticizing effect of water by the thermodynamic parameters

Shimazaki

Tashiro

Kumagai

et al. 2017

Bioscience, Biotechnology, and Biochemistry

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Relation between the thermodynamic parameters obtained from water sorption isotherms and the degree of reduction in the glass transition temperature (T), accompanied by water sorption, was quantitatively studied. Two well-known glassy food materials namely, wheat gluten and maltodextrin were used as samples. The difference between the chemical potential of water in a solution and that of pure water ([Formula: see text]), the difference between the chemical potential of solid in a solution and that of a pure solid ([Formula: see text]), and the change in the integral Gibbs free energy ([Formula: see text]) were obtained by analyzing the water sorption isotherms using solution thermodynamics. The parameter [Formula: see text] correlated well with ΔT (≡T - T; where T is the glass transition temperature of dry material), which had been taken to be an index of plasticizing effect. This indicates that plasticizing effect of water on foods can be evaluated through the parameter [Formula: see text].

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Gibbs energies, enthalpies, and entropies of water and lysozyme at the inner edge of excess hydration

Cited by 14 publications

References 53 publications

α-chymotrypsin in water-acetone and water-dimethyl sulfoxide mixtures: Effect of preferential solvation and hydration

α-chymotrypsin in water-acetone and water-dimethyl sulfoxide mixtures: Effect of preferential solvation and hydration

Diffusive and quantum effects of water properties in different states of matter

Analysis of water sorption isotherms of amorphous food materials by solution thermodynamics with relevance to glass transition: evaluation of plasticizing effect of water by the thermodynamic parameters

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