H/D isotope effects on protein hydration and interaction in solution

Rok, strany: 2006, 303 - 311

An approach has been suggested to study the H/D isotope effect on protein-water and protein-protein intermolecular interactions by determining the content of non-freezing water using low-temperature ¹H NMR in mixed (H2O/D2O) water solutions. Direct data are obtained on the amount of H2O adsorbed (absolute hydration) in presence of the heavy isotope (deuterium D), and isothermals of H2O/D2O fractionation at protein surface groups are presented for temperatures between –10 °C and –35 °C and solutions of varying composition. The fractionation factor, &phis; = [x/(1 – x)]/[x0/(1 – x0)], where x and x0 are the fractions of deuterons in hydration and bulk water, respectively, appeared to be extremely high: &phis; ≫ 1 at 0.03 < x0 < 0.10. The high values of &phis; indicate a decrease in apparent hydration of protein molecules. A probable reason of the effect can be an inter-protein molecular solvent-mediated interaction induced by D2O. The excess of &phis; over 1 appears to provide a quantitative estimate of the fraction of hydration water affected by such interaction.

ISO 690:

Goryunov, A. 2006. H/D isotope effects on protein hydration and interaction in solution. In General Physiology and Biophysics, vol. 25, no.3, pp. 303-311. 0231-5882.

APA:

Goryunov, A. (2006). H/D isotope effects on protein hydration and interaction in solution. General Physiology and Biophysics, 25(3), 303-311. 0231-5882.