Synthesis And Mechanism Studies Of The Cleavage Reagents And Their Conjugation With ODN

With the rapid development of Molecular Biology, the researchers of different scientific background are provided with a good opportunity to enter the field. People can resolve some important difficult problems with all kinds of research methods and knowledge in their fields. It is chemists' tribute that they design and synthesize effective nucleic acid cleavage reagents and clarify the reaction mechanism of complexes and DNA, which makes it possible to search effective remedial reagents and structural probes by molecular design.In this paper, a series of transition metal complexes were synthesized; interaction and reaction mechanism between complexes and DNA were studied. In addition, we synthesized and analyzed a sequence-specific cleavage reagent, in which oligodeoxynucleotide was recognizing group. Detailed work mentioned below were carried out:1. We have synthesized some metal complexes of with 1,10-phenanthroline and 1,10 phenanthroline -5,6-dione as ligands and ascertained their rough structures with infrared spectra, nuclear magnetic resonance spectra, molar electrolytic conductivity and elemental analysis.2. The new compound of [Cu(phen)2( -IDA)Cu(Phen)](C104)2.CH3OH has been designed, synthesized and characterized by X-ray diffraction analysis. In this dinuclear complex, it is worthy of notice that the source of tridentate chelate atoms (1N2O) of IDA is different from that of the reported complex. In all those complexes, no matter which conformation IDA assumes (mer- or fac-style), the two 0 atoms of 1N2O are both from carboxylic hydroxyl. However, by comparing the bond length, we can find that O(4) and O(2) atom is from different group in this complex, 0(4) atom from carboxylic hydroxyl, whereas, 0(2) from carboxylic carboxide. Another O atom from carboxylic hydroxyl, O(l), with Cu(l) and are located in equatorial plane with N(2) and N(4) from 1,10-phenanthroline. In this sense, IDA plays dual effects, tridentate chelating to Cu(2) and bridgebetween two Cu(1) andCu(2).3 Metal complexes were selected as the appropriate for the study of cleavage plasmid pBR322DNA by gel electrophoresis technique. The results showed Ni and Mn complexes could cleave effect- ively DNA in the presence of H2O2 at physiological pH and temperature, whereas individual Zn complex could cleave effectively DNA. Furthermore, we studied the reaction mechanism of Zn complex and DNA by added hydrogen peroxide, radical scavengers, rigorously anaerobic experiments, analysis for malondialdehyde-like products and the action with an Activated Phosphate Diester BDNPP. We conclude that Zn complex is a good hydrolytic cleavage reagent.4. By using absorption spectra method and EB as a fluorescence probe, we studied the action modes of the complexes binding to DNA. The results showed Mn and Ni complexes possibly bind to DNA by the mode of interaction, whereas Zn complex possibly bind to DNA by the modes of interaction and electrostatic binding.5. In addition, we conjugated cleavage system with recognize system and analyzed joint products by HPLC, which provide experimental basic for design of dual effects cleavage.