The Synthesis And Biological Evaluation Of Novel Nuclease Cleavage Agents

Artificial nuclease can mimic the function of natural nuclease by breaking the backbone of DNA site-specifically. And these small molecules can also be used as molecular biology tools and gene therapy agents. The present dissertation reported the design and synthesis of a series of artificial nuclease, and their detailed DNA binding and DNA cleavage behaviors were also studied.Oligopolyamide-IDB compounds were synthesized by HOBt/DCC coupling reaction and characterized by1H NMR, ESI-MS and IR spectra. And the fragment pathway of these compounds was studied by ESI-MS.Subsequently, the Zn (Ⅱ) complexes were obtained by reacting with Zn(ClO4)2as cleavage agents. The optimum condition of cleavage reaction was found by gel electrophoresis:the pUC18DNA can be linearized in Tris-HCl buffer (pH=8.92) at50℃for6h. With increasing of concentration, a new band can be observed and the molecular weight was about1000bp. This result shows that the Zn (II) complexes can cleave the duplex DNA efficiently, bearing some selectivity.Besides, the interaction between the novel complexes and DNA was studied by UV-Vis, CD and Fluorescence spectral. The data showed that the Kapp value of the complex is16-fold heavier than that for the compound without oligopolyamide. And also, experimental data indicated that introduction of oligopolyamide lead to increasing of binding affinities to A-T rich DNA sequences. Further, the electrostatic interaction between DNA and complexes has been proved by CD and fluorescence spectrometry.