The Enhanced Enzymolysis Resistance Of DNA Caused By Hybridizing With Morpholino

Nucleic acids, as the one of the most important biomolecules essential to life, attract plenty of interests as a result of their ability to carry genetic information. Besides the research in the field of gene, the nucleic acids also serve as an important material for molecular devices. They can be used to construct biosensors and other biomolecular devices for nucleic acids analysis, the study of DNA-protein interaction, disease diagnosis and even environmental trace detection. For the properties of natural nucleic acids limit their practical applications, the synthetic analogs of nucleic acids are considered as the substitutes in these fields, in which Morpholino (MO) is a typical one with good solubility and stability. Since the necessity of DNA/RNA in the construction of nucleic acid molecular devices, the study on the stability of DNA-MO double strand is of great importance.In this work, electrochemical method was used to study the protection effect of surface-immobilized MO to its complementary DNA against nuclease enzymolysis. The results suggest that MO is fit to be used in the construction of nucleic acids molecular devices with higher stability. Moreover, preliminary study of the modification, hybridization and enzymolysis of DNA on the gold nanoparticles were carried out. The scattering spectrum of single nanoparticle was also applied to explore the enzymolysis resistance of the nucleic acids on gold nanoparticles.1 The enhanced enzymolysis resistance of surface-immobilized DNA caused by hybridizing with morpholinoIn this chapter, DNA-SH/MO-SH strands of the same sequence were modified at the surface of gold electrode and ferrocene was labeled to the end of the strand as the electrochemical active group. The anti-enzymolysis capability of surface attached DNA, MO single strands, and DNA-DNA, MO-DNA double strands in DNase I solution were studied using cyclic voltammetry. The results show that MO single strand has a good enzymolysis resistance and it can also protect its complementary DNA against enzyme cleavage when they form double strand. Fluorescence polarization measurements suggest that the steric hindrance of MO is the main cause of the improved anti-enzymolysis ability of DNA in MO-DNA double strands.2 The preliminary study of nucleic acids stability against nuclease on gold nanoparticleGold nanoparticle is a kind of important material in the construction of nucleic acids molecular devices because of its unique biochemical properties. In this chapter, DNA-SH/MO-SH was immobilized on the gold nanoparticle according to Au-S interaction. TEM and UV-vis spectrum were used to study the modification, hybridization and enzymolysis of DNA/MO on gold nanoparticles. Besides, we developed an easy method to immobilize the gold nanoparticles on glass slide and conducted the preliminary study of single nanoparticle scattering spectrum. The results set a good stage for future work.