Proton transfers in biological mechanisms

Abstract

Proton transfers with concomitant charge translocation have a key role in many biological mechanisms. The transfers occur by changes in the relative depth of the minima in double minimum potential energy functions of the hydrogen bonds caused by environmental influences. Illustrative examples are the proton translocations in bacterial and visual rhodopsin, possibly in some neurotransmitter receptor activation and in the enzymatic proteolysis. The presentation of these examples is complemented by the results of ab initio calculations on pertinent model systems in vacuo and with inclusion of continuum solvent effects. Although the energetic frame for the changes in the relative depth of the double minimum proton potential function may be set by such calculations, the dynamic aspects of interactions between mechanistically important hydrogen bonds and their surrounding protein remain to be treated by more complex approaches.