Evaluation of dispersion-corrected density functional theory (B3LYP-DCP) for compounds of biochemical interest.
An evaluation of a dispersion-corrected density functional theory method (B3LYP-DCP) [I.D. Mackie, G.A. DiLabio, Interactions in large, polyaromatic hydrocarbon dimers: application of density functional theory with dispersion corrections, J. Phys. Chem. A 112 (2008) 10968-10976] for three systems of biochemical interest is presented. Firstly, structures and energies of isomers of the tripeptide Phe-Gly-Phe have been compared with CCSD(T)/CBS//RI-MP2/cc-pVTZ literature values. In the system aromatic interactions compete with XH-pi (X=C, N) interactions and hydrogen bonds which makes it a reliable model for proteins. The resulting mean absolute deviation between B3LYP-DCP and CCSD(T)/CBS relative energies is found to be 0.50 kcal mol(-1). Secondly, a phenylalanine derivative featuring a CH-pi interaction has been investigated. A comparison between the optimized geometry and X-ray crystal data shows that B3LYP-DCP accurately predicts the interaction between the two aromatic rings. Thirdly, the dipeptide Ac-Phe-Phe-NH(2) which contains an edge-to-face interaction between two aromatic rings has been studied. The study demonstrates the general applicability of the B3LYP-DCP method on systems which features interactions typically present in biochemical compounds.
Lill
Sten O Nilsson
SO
Department of Chemistry, University of Gothenburg, SE-412 96 Göteborg, Sweden. stenil@chem.gu.se
D018360:Crystallography, X-Ray; D004151:Dipeptides / Q000737:chemistry*; D006860:Hydrogen Bonding; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics; D014732:Vibration
D004151:Dipeptides; C119138:N-acetylphenylalanyl-phenylalanine; C026650:phenylalanylphenylalanine