Evaluation of the binding energy for hydrogen-bonded complexes containing amides and peptides

A polarizable dipole–dipole interaction model, which explicitly contains the permanent dipole–dipole interactions, the polarization interactions, the van der Waals interactions and the covalent interactions, is established to estimate the binding energies for hydrogen-bonded complexes containing amides and peptides. This polarizable dipole–dipole interaction model is applied to a series of hydrogen-bonded complexes, such as amide-amide dimers, N-methylformamide chains and β-sheet models. The calculation results show that our model not only can predict the binding energies in good agreement with those obtained from the CP-corrected MP2/aug-cc-pVTZ calculations, much better than those obtained from the three well-known AMBER99, CHARMM27 and OPLSAA/L force fields, but is very efficient as well, demonstrating that the model proposed in this work is useful. Based on the results obtained from our model, the natures of the hydrogen bonding interactions in these hydrogen-bonded complexes are discussed.