Dynamic behavior and some of the molecular properties of water molecules in pure water and in magnesium chloride solutions

Struis, Rudolf Paul Wilhelm Jozef; Bleijser, J. De; Leyte, J. C.

doi:10.1021/j100290a069

Cited by 109 publications

(64 citation statements)

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“…The average of 261 kH z Unauthenticated Download Date | 5/11/18 5:29 PM from Table 4 is probably about 3% too large, as we know th at the gas phase coupling calculated on the same level of approxim ation is 3% larger than the experimental value. The corrected value for the liquid is then 254 kH z in excellent agreement with the newest experimental values of Leyte and coworkers [24,25] H indm an and coworkers [26] of 258.6 kHz. We cannot give an accurate error for our coupling constant but would estimate it to be of the same size as the above experimental errors, i.e.…”

Section: Unauthenticatedsupporting

confidence: 86%

Calculation of Quadrupole Coupling Constants: From Gas to Liquid

Huber

1994

Zeitschrift Für Naturforschung A

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Section: Unauthenticatedsupporting

confidence: 86%

Calculation of Quadrupole Coupling Constants: From Gas to Liquid

Huber

1994

Zeitschrift Für Naturforschung A

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“…The 17 O QCC is determined by the electron distribution around the water oxygen and, hence, is affected by hydrogen-bond-induced electronic polarization (Cummins et al, 1985). The values for x I in ice Ih, liquid, and vapour are, respectively, 6.5 MHz (Spiess et al, 1969;Edmonds & Zussman, 1972), 8.1 MHz (van der Maarel et al, 1985Struis et al, 1987;Eggenberger et al, 1993), and 10.2 MHz (Verhoeven et al, 1969). An estimate of the 17 O QCC for the internal water molecules of BPTI may be obtained as follows.…”

Section: Internal Watermentioning

confidence: 99%

Protein Hydration Dynamics in Aqueous Solution: A Comparison of Bovine Pancreatic Trypsin Inhibitor and Ubiquitin by Oxygen-17 Spin Relaxation Dispersion

Денисов

Halle

1995

Journal of Molecular Biology

162

177

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Water oxygen-17 spin relaxation was used to study hydration and dynamics Condensed Matter Magnetic Resonance Group, Chemical of the globular proteins bovine pancreatic trypsin inhibitor (BPTI) and ubiquitin in aqueous solution. The frequency dispersion of the longitudinal Center, Lund University P. O. Box 124, S-22100 Lund and transverse relaxation rates was measured over the Larmor frequency Sweden range 2.6 to 49 MHz in the pD range 2 to 11 at 27°C. While the protein-induced relaxation enhancement was similar for the two proteins at high frequencies, it was an order of magnitude smaller for ubiquitin than for BPTI at low frequencies. This difference was ascribed to the abscence, in ubiquitin, of highly ordered internal water molecules, which are known to be present in BPTI and in most other globular proteins. These observations demonstrate that the water relaxation dispersion in protein solutions is essentially due to a few structural water molecules buried within the protein matrix, but exchanging rapidly with the external water. The relaxation data indicate that the internal water molecules of BPTI exchange with bulk water on the time-scale 10 −8 to 10 −6 second thus lowering the recently reported upper bound on the residence time of these internal water molecules by four orders of magnitude, and implying that local unfolding occurs on the submicrosecond time-scale. The water molecules residing at the surface of the two proteins were found to be highly mobile, with an average rotational correlation time of approximately 20 picoseconds. For both proteins, the oxygen-17 relaxation depended only very weakly on pD, showing that ionic residues do not perturb hydration water dynamics more than other surface residues. We believe that the present results resolve the long-standing controversy regarding the mechanism behind the spin relaxation dispersion of water nuclei in protein solutions, thus establishing oxygen-17 relaxation as a powerful tool for studies of structurally and functionally important water molecules in proteins and other biomolecules.

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“…Even for water molecules coordinated to ions, such as (Halle and Wennerström, 1981b), (Denisov and Halle, 1995c), and (Thomann et al, 1995), and for water adsorbed on NaX zeolite (Resing, 1976), the QCCs seem to differ little from the ice Ih value. In bulk water, however, the QCCs are 20%-25% larger than in ice Ih but virtually independent of temperature (van der Maarel et al, 1985(van der Maarel et al, , 1986Struis et al, 1987;Ludwig et al, 1995). These larger values are probably more appropriate for water molecules at the protein surface than for internal water molecules.…”

Section: Quadrupole Coupling Constantsmentioning

confidence: 99%

“…In the case of chemical-shift modulation (CSM), the relevant situation is one where water nuclei exchange between a bulk environment and an arbitrary number of protein-associated environments, each characterized by a fractional equilibrium population a mean residence time an intrinsic transverse relaxation rate and an intrinsic chemical shift For protein solutions, it is usually justified to assume that all exchange processes occur via the bulk, that and that Under these conditions (Swift and Connick, 1962) If exchange is also fast compared to the shift difference, then…”

Section: Chemical-shift Modulationmentioning

confidence: 99%