Study on Interactions between Paeonol and Cadherin

Paeonol has inhibitory effect on a variety of tumor cells, whereas cadherin is a kind of glycoprotein that is associated with the occurrence and development of different tumor. In this study, the interactions of paeonol and E. cadherin have been investigated by fluorescence spectrometry and atomic force microscopy (AFM). Fluorescence spectrometry results revealed that the addition of paeonol significantly quenched the fluorescence of E. cadherin. Based on the results of the quenching constant, it was inferred that the interaction of paeonol and E. cadherin was a static quenching process. The thermodynamic parameters Delta H and Delta S were calculated to be -4.3 x 10(5) J/mol and -1.3 x 10(3) J/(mol.K), respectively, which proved the involvement of weak interactive forces such as hydrogen bond van der Waals force. AFM results revealed that cadherin molecules were assembled into the long. chain structure. The addition of paeonol could significantly disrupt these assembling structures into short chains, which could be ascribed to the damage of the interdigitation model from the adjacent cadherin molecules. All these results reveal that cadherin is an important target of paeonol to modulate its activity.