The Study Of Hydrolysis Of Oligodeoxyribonucleotide With PNA As Recognization Moiety

The interaction of chemical molecules and biological ones, especially sequence specific recognition and site-specific cleavage of DNA have many applications such as in DNA sequence determinations, chromosome analyses, gene therapeutics, and recombinant DNA manipulation. So it is significant to develop artificial enzymes for the scission of nucleic acid with high activity and selectivity at normal condition. Meanwhile, with the nanoparticle pervading into the biological sciences, using the nanotechnology to study and resolve the problem of life sciences is becoming one of the most advanced fields. In this thesis, we had systematically studied the two items and obtained several conclusions below.(1) It is necessary to study the recognition of recognizing system to the target in order to study the cleavage of the site-specific artificial nuclease. A new method-fluorescence quenching and the probe ST (safranine T) was used to detect the formation of PNA-DNA hybrid and dissociation. The experiment showed that the hybrid of PNA-DNA can form easily under the normal conditions and it wouldn't dissociate until 85C. It is out of question to be used in the site-specific cleaving experiments at physiological conditions.(2)It's also necessary to investigate the cleavage system in order to study the site-specific artificial nuclease. Ultraviolet-visible spectrophotometry (UV) and cyclic voltammetry(CV) were used to study the complexes of several kinds of amino acids. The results demonstrated that complexes formed under the condition of weak acidity. We also synthesized a new trinuclear copper(II) complex [Cu3(L)2](ClO4)2 and the complex has been found to promote cleavage of pBR322 DNA from supercoiled form I to the open circular form II and to linearized form III. Spectroscopy was utilized to explore the interactional mechanism.(3) PNA-Cerium complex was synthesized and worked as the artificial site-specific nuclease, and it was characterized by MALDI-TOF mass spectroscopy. And fluorescence quenching was used to investigate the hybridization of 10 mers PNA and 26 mere ODN which was complementary partially. Then the sequence-specific cleavage of 26-mers ODN was studied by Ce4+ complex with PNA sequence recognizing moiety and the electrophoresis experimental results were satisfactory.Additionally, the artificial nuclease was linked with nanoparticle and the steric effect of Au collide to the PCR was researched.