Study on the interaction between curcumin and CopC by spectroscopic and docking methods.

Curcumin is a widely studied polyphenolic compound which has a variety of biological activity as anti-inflammatory and antitumor drugs. Recent research reported that copper chaperone binding with small molecular may relate to the treatment of cancer. In this work, the interaction between curcumin and CopC has been investigated in detail by means of UV-vis absorption, FTIR, CD, fluorescence spectroscopic and molecular docking methods The results showed that the CopC conformation was altered by curcumin with reduction of β-sheet and increase of random coil. Furthermore, curcumin can form a host-guest inclusion supramolecular complex with curcumin, and the forming constant had been calculated to be (2.85±0.21)×105 M-1 . In addition, the binding ability between Cu2+ and curcumin was less than that between Cu2+ and CopC. Moreover, the binding of curcumin with Cu2+ has an effect on the binding ability between curcumin and CopC. The thermodynamic parameters ΔH and ΔS at different temperatures were obtained. The formation of CopC-curcumin complex depended on the hydrophobic force, and the binding average distance between CopC and curcumin was determined. What's more, the binding site of curcumin to CopC was shown vividly by an automated public domain software package ArgusLab 4.0.1.