Characterization of the Structure of PDP-DPPC Bilayers by DFT and PM3 Calculations

摘要

The character of 3-pentadecylphenol(PDP)-dipalmitoylophosphatidylcholine(DPPC)interactions in a bilayer system was investigated using DFT and semi-empirical calculations.The obtained results were supported by ATR-IR spectra.The strongest inter-molecular hydrogen bond was found between the phenolic OH and the PO_2~-groups of the DPPC molecule.The presence of water and hydrocarbon chains slightly weakens the strength of this PDP-DPPC interaction.In contrast to a pure DPPC bilayer,the water molecules do not destroy the H-bonds formed by PO_2~-moieties and even enhance the total energy of the interaction.Both the van der Waals' interactions in the hydrophobic core of the PDP-DPPC aggregate and the intermolecular H-bond in the hydrophilic part make this complex more rigid,which influences its physical and chemical properties.