The Activity Regulation Of Functional Nucleic Acid8-17DNAzyme

Functional nucleic acids, are not only the vector of genetic information, but alsohave some other new functions such as catalysis, regulation of gene expression andspecific binding.etc. Recently, both natural and synthetical functional nucleic acidshave attracted more and more attention. Especially with the discovery of nonexpressionsmall RNA and regulatory RNA, people ’s understanding of the nucleic acids have athroughly changed. But researches on the control of functional nucleic acids arelimited, if the functional nucleic acids can be controlled, it will help us to figure outthe mechanism of functional nucleic acids and regulate the gene drugs to achieve theanticipant curative effects.DNAzyme is one of the representative functional nucleic acids which were disc-overed in recent years. DNAzyme has many biological catalytic functions, such asshearing RNA molecules or DNA molecules, T4nucleotide kinase-like activity, DNAligases-like activity and catalytic activity on ionization of porphyrin metal. This thesisfocused on8-17DNAzyme, a study on the active regulation of RNA shearing activityby controlling DNAzyme’s topology structure was proposed. The purpose of oursdudy is to establish an activity regulation model of DNAzyme.We hope our researchcould induce some new thoughts in the regulation of functional nucleic acids by chan-ing their topological structures.Our result showed that the specific catalytic activity of8-17DNAzyme on hy-drolysis of RNA phosphodiester linkage will be reduced greatly after cyclization of8-17DNAzyme by T4DNA ligase. When8-17DNAzyme was designed into a bighairpin structure, activity was also reduced, because its two ends were close to eachother. When the stem area of the hairpin structure was cut off by restriction endonu-clease EcoR I, the two closed ends of8-17DNAzyme would separate. Then theRNA shear activity of DNAzyme’s would recover. As showed in the thesis, the regula-tion of a functional nucleic acid was controlled by an enzyme.Our study realized to the activity of functional nucleic acid by control the topolo-gical structure of8-17DNAzyme. An activity regulation model of DNAzyme wasestablished. Our research will be helpful to the further study on the relationship of structure and function of DNAzyme. It will shed sunshine on the research on DNAgenetic analysis, diagnosis, gene therapy and other practical application. Also, ourresearch will be helpful to regulation the activities of other functional nucleic acids.