Interaction Analyses between Calcite/Apatite and Peptides by Fragment Molecular Orbital Method

We have analyzed the interaction between calcite / hydroxyapatite and peptides by using the pair interaction energy decomposition (PIEDA) analysis of the fragment molecular orbital (FMO) method, based on interest in the biomineralizations. Furthermore, we have performed a multiple regression analysis using PIEDA results as well as structural data to clarify important factors of the interaction energies. As a result, it was found that "Interaction with short-range fragment" is an essential descriptor in the calcite system and also that "Distance between residue and surface of crystal" plays an important role in the hydroxyapatite system. This contrast reflects that the electrostatic interaction dominates in the former system but the charge-transfer has an additional effect in the latter.