Interaction Of Dihydrazone And Copper Complexes With CopC

1. In this paper,2,6-pyridine-dicarboxylic acid was as the material.2, 6-pyridine diformylhydrazine 2-hydroxylnaphthene carboxylic hydrazone (L1) and 2,6-pyridine-diformylhydrazine salicylhydrazide (H2L2) were synthesized by acylation, esterification and aminolysis reaction, successively. The structures of the ligands were verified by UV-vis absorption spectrum, fluorescence spectrum, infrared spectroscopy, molar conductance, nuclear magnetic resonance spectroscopy and elemental analysis. The ligands structures were studied in the acid-base condition by the spectroscopic.2. Firstly,2,6-pyridine-diformylhydrazine-2-hydroxylnaphthene carbox-yichydrazone complex (copper complex 1) and 2,6-pyridine-diformylhydraz-ine salicylhydrazide complex (copper complex 2) were synthesized by refluxing. Secondly, the structure of the copper complex 1 and 2 copper complex was characterized by UV-vis absorption spectrum, fluorescence spectrum, infrared spectroscopy, electrospray ionization mass spectrometry and elemental analysis. Finally, the structural formulas provided the copper complex 1 and copper complex 2.3. Human Serum Albumin (HSA) was selected as a model protein. The interaction between ligands, copper complexes and HSA was studied by fluorescence, UV-Vis absorption spectrum and fluorescence lifetime measurement. Reasearch results indicated that blue shift occurred at 278 nm absorption peak and fluorescence quenching occurred, which was static quenching, at 334 nm emission peak of HSA interaction with ligands and copper complexes. The number of binding sites (n) was one and the forming constant (Ka) had been calculated to be 105 M-1. According to the thermodynamic parameters, it is likely that hydrophobic and hydrogen bond interaction. And the binding average distance between HSA and ligands, copper complexes was determined by the radiation theory of resonance energy transfer. The interaction mechanism of ligands to HSA was shown vividly by an automated public domain software package ArgusLab 4.0.1 and PyMOL, which was confirmed the radiation theory of resonance energy transfer of results.4. The interaction between ligands, copper complexes and CopC was studied by fluorescence, UV-Vis absorption spectrum and fluorescence lifetime measurement. Reasearch results indicated that fluorescence quenching was static quenching at 320 nm emission peak of CopC interaction with ligands and copper complexes. The number of binding sites (n) was one and the forming constant (Ka) had been calculated to be 105 M-1. According to the thermodynamic parameters, it is likely that hydrophobic and hydrogen bond interaction. And the binding average distance between CopC and ligands, copper complexes was determined by the radiation theory of resonance energy transfer. The CopC protein is proposed to be a copper chaperone protein, which played a role of redox switch function. Cu2+ titrated mixed (ligand-CopC) solution, which indicated that binding affinity of CopC binding Cu2+ and ligands binding Cu2+was weaken. In addition, the stoichiometric ratio of CopC, ligands and Cu2+ was 1:1, respectively. Fluorescence spectrum experiment of copper complexes titratig CopC, which indicated composites formed between copper complexes and CopC. These results illustrated that the formation of a ternary complex among Cu, ligand and CopC. Finally, the interaction mechanism of ligands to CopC was shown vividly by an automated public domain software package ArgusLab 4.0.1 and PyMOL, which was confirmed the radiation theory of resonance energy transfer of results.