Water structure-dependent charge transport in proteins.

Dielectric and conductivity measurements are reported for bovine serum albumin as a function of hydration. Strong evidence is found for the existence of mobile charges whose short- and long-range hopping motion strongly depends on the physical state of the protein-bound water. These charges are considered to be protons. Insights into the nature of the electrical properties of protein-methylglyoxal complexes are provided, and the possibilities for correlated proton-electron motions are outlined.