Show simple item record

dc.contributor.authorFadda, Elisa
dc.contributor.authorWoods, Robert J.
dc.identifier.citationFadda, Elisa; Woods, Robert J. (2013). Contribution of the empirical dispersion correction on the conformation of short alanine peptides obtained by gas-phase qm calculations. Canadian Journal of Chemistry 91 (9), 859-865
dc.description.abstractIn this work we analyze the effect of the inclusion of an empirical dispersion term to standard DFT (DFT-D) in the prediction of the conformational energy of the alanine dipeptide (Ala2) and in assessing the relative stabilities of short polyalanine peptides in helical conformations, i.e., alpha and 3(10) helices, from Ala4 to Ala16. The Ala2 conformational energies obtained with the dispersion-corrected GGA functional B97-D are compared to previously published high level MP2 data. Meanwhile, the B97-D performance on larger polyalanine peptides is compared to MP2, B3LYP and RHF calculations obtained at a lower level of theory. Our results show that electron correlation affects the conformational energies of short peptides with a weight that increases with the peptide length. Indeed, while the contribution of vdW forces is significant for larger peptides, in the case of Ala2 it is negligible when compared to solvent effects. Even for short peptides, the inclusion of an empirical dispersion term greatly improves accuracy of DFT methods, providing results that correlate very well with the MP2 reference at no additional computational cost.
dc.publisherCanadian Science Publishing
dc.relation.ispartofCanadian Journal of Chemistry
dc.rightsAttribution-NonCommercial-NoDerivs 3.0 Ireland
dc.subjectalanine dipeptide
dc.subjectshort polyalanine peptides
dc.subjectab initio and dft calculations
dc.subjectempirical dispersion-corrected dft
dc.subjectpeptides structure and stability
dc.subjectramachandran plot
dc.subjectdensity-functional theory
dc.subjectmolecular-dynamics simulations
dc.subjection mobility spectrometry
dc.subjectder-waals interactions
dc.subjectnoncovalent interactions
dc.titleContribution of the empirical dispersion correction on the conformation of short alanine peptides obtained by gas-phase qm calculations

Files in this item


This item appears in the following Collection(s)

Show simple item record

Attribution-NonCommercial-NoDerivs 3.0 Ireland
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivs 3.0 Ireland