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- All Subjects: Threose Nucleic Acid
- All Subjects: Biological Stability
- Creators: Larsen, Andrew
- Creators: Meyers, Madeline Ashby
Description
DNA is a natural genetic polymer capable of storing and preserving genetic information in biological systems. Due to its natural information storage capacity, recent scientific progress demonstrates that DNA has the potential to exceed standard information storage technologies. However, DNA is limited in its information storage capacities due to its susceptibility to degradation in the presence of naturally occurring nucleases. Threose nucleic acid (TNA), an unnatural genetic polymer with a 3'->2'phosphodiester-linked threose sugar backbone, has promising potential to overcome this limitation. TNA is not a substrate for natural nucleases and thus shows a dramatic increase in stability compared to DNA. However, TNA transcription has a tendency to generate G:G mispairs and lead to a gradual loss of information within the template. It was hypothesized that the mutation occurs through a G:G Hoogsteen base pair that forms preferentially over the canonical G:C Watson-Crick base pair. Incorporation of 7-deaza-dG into a four letter template effectively eliminated G:G mispairings and improved the replication fidelity from 60% to 99.6% with only four errors in a thousand. These results have laid the groundwork for further research to increase the length of the TNA product synthesized and to test TNA's ability to store genetic information.
ContributorsMeyers, Madeline Ashby (Author) / Chaput, John C. (Thesis director) / Chandler, Douglas (Committee member) / Dunn, Matthew R. (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2014-05
Description
Nucleic acid polymers have numerous applications in both therapeutics and research to control gene expression and bind biologically relevant targets. However, due to poor biological stability their clinical applications are limited. Chemical modifications can improve both intracellular and extracellular stability and enhance resistance to nuclease degradation. To identify a potential candidate for a highly stable synthetic nucleic acid, the biostability of α-L-threofuranosyl nucleic acid (TNA) was evaluated under simulated biological conditions. TNA contains a four-carbon sugar and is linked by 2’, 3’ phosphodiester bonds. We hypothesized that this distinct chemical structure would yield greater nuclease resistance in human serum and human liver microsomes, which were selected as biologically relevant nuclease conditions. We found that TNA oligonucleotides remained undigested for 7 days in these conditions. In addition, TNA/DNA heteropolymers and TNA/RNA oligonucleotide duplexes displayed nuclease resistance, suggesting that TNA has a protective effect over DNA and RNA. In conclusion TNA demonstrates potential as a viable synthetic nucleic acid for use in numerous clinical and therapeutic applications.
ContributorsCulbertson, Michelle Catherine (Author) / Maley, Carlo (Thesis director) / Mangone, Marco (Committee member) / Larsen, Andrew (Committee member) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12