Li M, Huang S, Ye C, Xie Y. Synthesis, structure, protein binding of Cu(II) complexes with a tridentate NNO Schiff-base ligand.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015;
150:290-300. [PMID:
26056979 DOI:
10.1016/j.saa.2015.05.064]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 05/11/2015] [Accepted: 05/23/2015] [Indexed: 06/04/2023]
Abstract
Four new Cu(II) complexes (1, 2, 3 and 4) in the presence of different anions (Cl(-), Br(-), I(-) and ClO4(-)) have been prepared by tridentate NNN Schiff-base ligand (N,N-dimethyl-N'-[phenyl(2-pyridyl)methylene]ethane-1,2-diamine) and well characterized by single-crystal X-ray diffraction, elemental analysis, IR and UV-Vis spectroscopy. The interactions of complexes 1-4 with human serum albumin (HSA) have been investigated in Tris-HCl buffer solution at pH 7.4 by spectroscopic methods and a molecular docking technique. Experimental results proved that the four complexes quench the fluorescence of HSA through a static quenching mechanism. Thermodynamic parameters were calculated from Van't Hoff equation. The distance r between the donor (HSA) and acceptor (complexes 1-4) has been obtained by means of Förester resonance energy transfer (FRET). Molecular docking results indicated that the main active binding sites for complexes 1, 2 and 4 are site III in subdomain IB and for complex 3 is site II in subdomain III A. The combination of molecular docking results and fluorescence experimental results indicate that the interaction between 1-4 and HSA are dominated by hydrophobic forces as well as hydrogen bonds.
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