Solvated electrons and protons in peptides and water

The role of hydrated electrons and protons is of great importance in many areas of physics, chemistry and biology. Despite of their ubiquitous presence, many fundamental aspects are not yet fully understood. Among structural aspects in finite size water aggregates, the solvation of electrons at the surface or in the interior of clusters  is still under debate. Further, the dynamics of the formation of cavities to accomodate an electron in water is still largely unexplored.

In our work, we employ mixed quantum/classical DFT molecular dynamics simulation methods to tackle these questions for medium-sized water cluster anions. In addition to the question of the structure of solvated electrons, we also investigate the process of solvation of an initially delocalized electron as a function of the cluster temperature. Building on this knowledge, the recombination reaction of electrons co-solvated  with a proton is investigated for the first time by means of ab initio molecular dynamics simulations. Currently the project is being extended toward proton transfer reactions between amino acids or small peptides and the surrounding water (formation of zwitter-ions) as well as proton transfer processes between side chains of a peptide (formation of salt bridges).

 

The project is funded through the MATHEON project A19.

Selected Publications

Ab Initio Molecular Dynamics Simulation of a Medium-Sized Water Cluster Anion:

 

  • From an Interior to a Surface Located Excess Electron via a Delocalized
    State T. Frigato, J. Van de Vondele, B. Schmidt, Ch. Schütte, P. Jungwirth J. Phys.Chem. A 112 (27), 6125-6133 (2008)

 

  • Hydrogen Forms in Water by Proton Transfer to a Distorted Electron O. Maršálek, T. Frigato, J. VandeVondele, S. E. Bradforth, B. Schmidt, Ch. Schütte, P. Jungwirth J. Phys. Chem. B 114 (2), 915-920 (2010)

 

  • Dynamics of Electron Localization in Warm vs. Cold Water Clusters O. Maršálek, F. Uhlig, T. Frigato, B. Schmidt, P. Jungwirth Phys. Rev. Lett. 105 (4), 043002 (2010)

 

  • Dynamics of Electron Localization in Warm vs. Cold Water Clusters. Marsalek, O. and Uhlig, F. and Frigato, T. and Schmidt, B. and Jungwirth, P. Phys. Rev. Lett. 105 (4), 043002 (2010)

 

  • Hydrogen Forms in Water by Proton Transfer to a Distorted Electron. Marsalek, O. and Frigato, T. and VandeVondele, J. and Bradforth, P. E. and Schmidt, B. and Schütte, Ch. and Jungwirth, P. J. Phys. Chem. B 114 (2), 915 (2010)

Head:

Christof Schütte

Project researchers

Burkhard Schmidt, Tomaso Frigato

 

Cooperations:

Prof. P. Jungwirth

(Czech Academy of Sciences, Prague)