Chemical Approaches To Study Modified Nucleic Acids

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dc.contributor.advisorHili, Ryan
dc.contributor.authorCauley-Le Fevre, Morgan Beatty Pierre
dc.date.accessioned2025-04-10T10:53:15Z
dc.date.available2025-04-10T10:53:15Z
dc.date.copyright2024-12-16
dc.date.issued2025-04-10
dc.date.updated2025-04-10T10:53:15Z
dc.degree.disciplineChemistry
dc.degree.levelMaster's
dc.degree.nameMSc - Master of Science
dc.description.abstractChemical modifications govern the fate and function of nucleic acids. The methylation of the N-6 position of adenosine (m6A) in RNA is the most studied naturally occurring modification. Methylation of this position is regulated by a complex, dynamic interplay between enzymes known as methyltransferases (writers) and demethylases (erasers). Modifications on functional nucleic acid polymers (aptamers), have also been reported to increase binding affinity and stability in vivo towards a particular target. Ligase-catalyzed OligOnucleotide polymERization (LOOPER) is a method to access hetermultivalent aptamers, and the method was successful in the evolution of a modified aptamer towards human α-thrombin. However, LOOPER requires a platform to produce these modified aptamers at scale. Chapter 2 of this thesis focusses on my work to create such a platform, using solid-phase DNA synthesis and orthogonal protecting groups. Two protecting groups were synthesized, and one, allyloxy carbonyl (alloc) was taken forward for this platform due to the ease of the solution-phase deprotection step. Synthesis of the modified phosphoramidite equipped with alloc was undertaken, and the phosphoramidite was eventually incorporated into an oligonucleotide. The protecting group was successfully removed on-instrument, however several coupling protocols to install the chemical modifiers for the aptamer were ultimately unsuccessful. In Chapter 3 of this thesis, I focussed on the optimisation of some hit compounds towards m6A demethylase ALKBH5, which has been shown to be up- or down-regulation in a variety of cancerous and non-cancerous disease. Selective inhibition of the protein would greatly facilitate knowledge generation around its associated pathologies. From two DNA-encoded library hits towards the protein, hit optimization synthesis of two molecules was performed. A fluorescence polarization (FP) assay to determine IC50 data from these compounds was produced and was successfully validated. Unfortunately, with little material of the two compounds generated, only limited FP data was generated, and the results were inconclusive.
dc.identifier.urihttps://hdl.handle.net/10315/42839
dc.languageen
dc.rightsAuthor owns copyright, except where explicitly noted. Please contact the author directly with licensing requests.
dc.subject.keywordsChemistry
dc.subject.keywordsNucleic acids
dc.subject.keywordsOrganic synthesis
dc.subject.keywordsOrganic chemistry
dc.subject.keywordsModified nucleic acids
dc.subject.keywordsAptamers
dc.subject.keywordsDemethylases
dc.subject.keywordsm6A
dc.subject.keywordsN6-methyladenosine
dc.subject.keywordsLOOPER
dc.subject.keywordsModified aptamers
dc.subject.keywordsInhibition
dc.titleChemical Approaches To Study Modified Nucleic Acids
dc.typeElectronic Thesis or Dissertation

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