Dielectric studies of proton transport in proteins

Various studies of the electrical and dielectric properties of proteins of low hydration content are reviewed to indicate that proton transport processes provide a major contribution to the effects that have been observed. New experimental data is described to show that the pH dependence of the low frequency dispersion in lysozyme is mainly associated with the transfer of protons between ionisable basic side groups in the protein structure. Such dielectric studies may usefully be extended to investigations of proton transfer processes in energy-transducing membranes, as well as forming the basis for the development of new biosensors.