Proton dynamics in an enzyme model substrate: an ab initio molecular dynamics study

We have investigated theoretically the influence of thermal fluctuations on the proton hopping properties of a model substrate for enzymatic reactions , benzoylacetone. Our calculations, based on the Car-Parrinello molecular d ynamics approach, indicate that proton transfer events occur on a very shor t time scale and they are accompanied by a concerted motion of the H-bond d onors towards the hydrogen. Possible implications of the latter finding for enzyme mechanism of action are discussed. (C) 2000 Elsevier Science B.V. A ll rights reserved.