Net-charge models in the analysis of ion and electron transfer in enzyme reactions

A number of key questions arising in the study of proton-relay chains and of the driving forces causing them to operate are discussed with main emphasis on the net-charge distribution of relevant model systems. Special reference is made to the role of water, histidine imidazole, and peptide bonds and to the description of hydride transfer in ADH-NAD+ complexes. Suggestions are given for treating H-bonds by the so-called Del Re method.