Specific binding and inhibition of 6-benzylaminopurine to catalase: Multiple spectroscopic methods combined with molecular docking study

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• 作者：Qin Xu ; Yanni Lu ; Longyun Jing ; Lijuan Cai ; Xinfeng Zhu ; Ju Xie ; Xiaoya Hu
• 关键词：Catalase ; 6-Benzylaminopurine ; Interaction ; Inhibition ; Docking
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：5 April, 2014
• 年：2014
• 卷：123
• 期：Complete
• 页码：327-335
• 全文大小：1832 K

文摘

6-Benzylaminopurine (6-BA) is a kind of cytokinin which could regulate the activities of the antioxidant defense system of plants. In this work, its interaction with and inhibition of beef liver catalase have been systematically investigated using spectroscopic, isothermal titration calorimetric and molecular docking methods under physiological conditions. The fluorescence quenching of beef liver catalase (BLC) by 6-BA is due to the formation of 6-BA-BLC complex. Hydrogen bonds and van der Waals interactions play major roles in stabilizing the complex. The Stern-Volmer quenching constant, binding constant, the corresponding thermodynamic parameters and binding numbers were measured. The results of UV-vis absorption, three-dimensional fluorescence, synchronous fluorescence and circular dichroism spectroscopic results demonstrate that the binding of 6-BA results in the micro-environment change around tyrosine (Tyr) and tryptophan (Trp) residues of BLC. The BLC-mediated conversion of H₂O₂ to H₂O and O₂, in the presence and absence of 6-BA, was also studied. Lineweaver-Burk plot indicates a noncompetitive type of inhibition. Molecular docking study was used to find the binding sites.