Effective dipole moment of protein-bound water

Dielectric data obtained at 100 kHz and 9.95 GHz for bovine serum albumin as a function of hydration are used to show the existence of a dielectric dispersion in the MHz range of frequencies. This dispersion is found to be directly related to the number of water molecules occupying the primary sorption sites of the protein; the effective dipole moment of these bound water molecules is calculated to be (2.6±0.1)× 10–30 C m (0.79±0.03 D).