Barrierless proton transfer within short protonated peptides in the presence of water bridges. A density functional theory study
Journal
Journal of Physical Chemistry B
Journal Volume
115
Journal Issue
6
Pages
1485-1490
Date Issued
2011
Author(s)
Abstract
We have used density functional theory at the B3LYP/6-31++G(d,p) level of theory to investigate proton transfer in protonated N2-acetyl-N 1-methylglycinamide and N-acetylglycyl-N1- methylglycinamide with multiwater assistance and to determine the structures and energies of the most important minima and transition states corresponding to the proton-transfer pathways. We propose mechanisms for proton transfer between adjacent and nonadjacent carbonyl oxygen atoms with water bridge assistance. The presence of a two-water bridge connected to the two carbonyl oxygen atoms provides a proton-transfer mechanism having such a low-barrier that the excess proton is almost freely mobile. © 2011 American Chemical Society.
SDGs
Type
journal article