Artificial Nucleases - Widowed Polyamide And Silk Groups Peptide Conjugates Synthesis Study

Chemical reagents used as tools of DNA or RNA cleavage in a sequence-specific way is a new kind of non-enzyme cleavage tool, which is called chemical nuclease or artificial nuclease . Artificial nuclease is an important tool in molecular biology and genetic engineering, it is also used as a kind of nucleic acid structure and function probe . Hence, it has very important sense of theoretics and applying value to find out highly efficient artificial nuclease reagent, especially cleavage reagent in a sequence-specific way. DNA or RNA cleavage reagents consist of two main parts: the one is cleavage system, the other is recognition system . Then, the two main parts are coupled with a link, the coupled compound can cut DNA or RNA sequence-specific groove .The synthesis method of a new artificial nuclease is developed in details in the dissertation . The products consist of polyamide used as recognition system and seryl-histidine dipeptide (Ser-His) used as cleavage system . The two main systems are connected with hexamethylene diamine as a link . In the process of synthesis, there are DCC/HOBt coupling reaction, Chloroform reaction, hydrogenation reaction used Pd-C as catalysts . The reaction condition is mild, the needed time is short and the yield of many compounds is good. Another reaction in the process of synthesis is getting rid of protecting group of amino acids .Some analysis tools and methods are very necessary in characterization of synthetic products, such as ¹H NMR, ¹³C NMR, Infrared spectroscopy, Electrospray ionization mass spectrometer (ESI-MS) and many two-dimensional nuclear magnetic resonance spectra. Some conclusions can be getted from a lot of data, they can be used as references to other analogues . For example, based on these conclusions it is very convenient to estimate how many N-methylpyrrole residues in one compound through ¹H NMR. Order of residues connection can be identified from fracture paths of compounds in electrospray ionization mass spectrometer . In order to make certain that impurity in synthetic compounds don't affect tests of biological activity, we makeuse of on-line testing of high performance liquid chromatography and ESI-MS to analyze the multistep synthetic polyamide/dipeptide conjugate0 Through preliminary tests, it is found that DNA cleavage activity of synthetic polyamide/dipeptide conjugates is several hundred times more than that of seryl-histidine dipeptide ?...