TY - JOUR
T1 - Tyrosine-glycine revisited
T2 - resolving the discrepancy between theory and experiment
AU - Holroyd, Leo Frederick
AU - van Mourik, Tanja
N1 - LFH acknowledges the Engineering and Physical Sciences Research Council for studentship support through the Doctoral Training Account scheme.
PY - 2015/2/4
Y1 - 2015/2/4
N2 - Energies of 20 conformers of the Tyr-Gly dipeptide were computed using DSD-PBEP86-D3BJ/aug-cc-VTZ, with geometries from M06-2X/6-31+G* and B97-D/6-31+G*. At 0 K, these energies support the earlier finding from MP2/6-31+G*//B3LYP/6-31+G*, that the most stable conformer is folded and H-bonded. However, when free-energy corrections at 400 K are added, non-H-bonded conformers are the most stable. This supports an earlier spectroscopic study in which H-bonded conformers were absent. Of the four most stable conformers at 400 K, two were not matched with spectra in the experimental study, but we argue that all four can in fact be plausibly assigned to the experimental spectra.
AB - Energies of 20 conformers of the Tyr-Gly dipeptide were computed using DSD-PBEP86-D3BJ/aug-cc-VTZ, with geometries from M06-2X/6-31+G* and B97-D/6-31+G*. At 0 K, these energies support the earlier finding from MP2/6-31+G*//B3LYP/6-31+G*, that the most stable conformer is folded and H-bonded. However, when free-energy corrections at 400 K are added, non-H-bonded conformers are the most stable. This supports an earlier spectroscopic study in which H-bonded conformers were absent. Of the four most stable conformers at 400 K, two were not matched with spectra in the experimental study, but we argue that all four can in fact be plausibly assigned to the experimental spectra.
UR - http://www.sciencedirect.com/science/article/pii/S0009261414010859
U2 - 10.1016/j.cplett.2014.12.055
DO - 10.1016/j.cplett.2014.12.055
M3 - Article
SN - 0009-2614
VL - 621
SP - 124
EP - 129
JO - Chemical Physics Letters
JF - Chemical Physics Letters
ER -
