中文摘要：

我们试图在催化 phosphodiesters 的水解作用探索基于 chitosan 的金属建筑群的角色。到这个目的，我们在催化的 chitosan 铜建筑群(CSCu ) 的动力学上执行了详细研究二度(4-nitrophenol ) 的水解作用在 Tris-H+ 缓冲区并且在器官的溶剂的磷酸盐(BNPP ) 。处于反应的率的重要改进(多达 3 吠敨吠 ? 爠獥汵獴椠摮捩瑡 ? 桴瑡琠敨琠敨浲污猠慴楢楬祴挠湡戠 ? 湥慨据摥眠瑩 ? 桴 ? 票牢摩穩瑡潩 ? 景猠汩捩 ? 慮潮慰瑲捩敬？

英文摘要：

We aimed to explore the role of chitosan-based metal complexes in catalyzing the hydrolysis of phosphodiesters To this end, we performed detailed studies on the kinetics of the chitosan copper complex （CSCu）-catalyzed hydrolysis of bis（4-nitrophenol） phosphate （BNPP） in Tris-H＋ buffer and in an organic solvent. A significant enhancement in the rate of reaction （up to 3 X 105-fold acceleration） was observed at pH 8.0 （25 ℃）. The pH depend- ence of BNPP hydrolysis at pH 5.5-9.5 and the UV spectra revealed that the copper-bounded water molecules un- derwent deprotonation to form the active catalytic species CSCu-OH. The kinetic behavior of BNPP catalytic hydrolysis in the Tris-H＋ buffer was consistent with that predicted by the Michaelis-Menten kinetics model. An in-ramolecular nucleophilic attack by the copper-bonded hydroxide group on the same activated phosphodiester substrate was proposed as the catalytic mechanism for CSCu-catalyzed reaction system. The results of DNA binding and cleavage experiments indicated electrostatic binding mode of CSCu to DNA as well as the strong capability of CSCu to disturb the supercoiled strand of DNA and cleave it to nicked circular form.