Journal
JOURNAL OF PHYSICAL CHEMISTRY B
Volume 112, Issue 45, Pages 14291-14295Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp805528v
Keywords
-
Categories
Funding
- National Science Foundation [EPS-0132618, CHE-0517067]
- American Chemical Society-Petroleum Research Fund [39739-B]
Ask authors/readers for more resources
To examine the effects of pi-stacking interactions between aromatic amino acid side chains and adenine bearing ligands in crystalline protein structures, 26 toluene/(N9-methyl)adenine model configurations have been constructed from protein/ligand crystal structures. Full geometry optimizations with the MP2 method cause the 26 crystal structures to collapse to six unique structures. The complete basis set (CBS) limit of the CCSD(T) interaction energies has been determined for all 32 structures by combining explicitly correlated MP2-R12 computations with a correction for higher-order correlation effects from CCSD(T) calculations. The CCSD(T) CBS limit interaction energies of the 26 crystal structures range from -3.19 to -6.77 kcal mol(-1) and average -5.01 kcal mol(-1). The CCSD(T) CBS limit interaction energies of the optimized complexes increase by roughly 1.5 kcal mol(-1) on average to -6.54 kcal mol(-1) (ranging from -5.93 to -7.05 kcal mol(-1)). Corrections for higher-order correlation effects are extremely important for both sets of structures and are responsible for the modest increase in the interaction energy after optimization. The MP2 method overbinds the crystal structures by 2.31 kcal mol(-1) on average compared to 4.50 kcal mol(-1) for the optimized structures.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available