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Updated: Jul 3, 2026

A New Straightforward Method for Lipophilicity (logP) Measurement using 19F NMR Spectroscopy
Published on: January 30, 2019
Measuring enzyme hydration in nonpolar organic solvents using NMR
M C Parker1, B D Moore, A J Blacker
1Department of Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, United Kindom.
Abstract:
A very sensitive NMR method has been developed for measuring deuterated water bound to proteins suspended in nonpolar solvents. This has been used to determine the amount of bound water as a function of water activity for subtilisin Carlsberg suspended in hexane, benzene, and toluene and for alpha-chymotrypsin in hexane. The adsorption isotherms for subtilisin in the three solvents are very similar showing that water activity can be usefully employed to predict the amount of water bound to proteins in nonpolar organic media. Comparison of the degree of enzyme hydration reached in nonpolar solvents with that obtained in air shows that adsorption of strongly bound water is hardly affected by the low dielectric medium, but adsorption of loosely bound water is significantly reduced. This suggests that the hydrophobic regions of the protein surface are preferentially solvated by solvent molecules, and that in a nonpolar environment formation of a complete monolayer of water over the protein surface is thermodynamically unfavorable. (c) 1995 John Wiley & Sons, Inc.
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