(292a) Boronate Ester-Based Dynamic Nucleic Acids for Templated Analyte Detection

Beyond storing genetic information, nucleic acids have become incredibly important tools for self-assembly, nanotechnology, drug delivery, and biosensing applications because of their unique molecular recognition properties. For example, in addition to recognizing complementary nucleic acid sequences, DNA and RNA have been used as molecular recognition agents called aptamers, which detect a variety of ligands, ranging from small molecules to proteins. Aptamers are generated for specific ligands by using systematic evolution of ligands by exponential enrichment (SELEX), in which the desired ligand is incubated with a large library of oligonucleotides and through repeated cycles of amplification, the oligonucleotides with the highest affinity for the ligand are selected. Alternatively, researchers have begun exploring the use of dynamic covalent chemistry to assemble synthetic nucleic acids in the presence of template molecules.

In this work, we develop a system that can be used for templated-assembly of synthetic nucleic acids based on dynamic boronate esters. The boronic acid-containing polymer was synthesized via a copolymerization of maleic anhydride and 4-vinylphenyl boronic acid. Maleic anhydride was included as a comonomer to improve water solubility and to achieve regular spacing of the boronic acid functionalities. Polymerization conditions, specifically solvent, temperature, and comonomer ratio, were varied in order to achieve an alternating structure. Apparent dissociation constants for four ribonucleosides (i.e., 5-methyluridine, cytidine, guanosine, and adenosine) were determined via a colorimetric, competitive binding assay with Alizarin Red S. The influence of buffer and DMSO content on ribonucleoside binding was investigated. By identifying conditions in which all four ribonucleosides bind to the polymer with similar affinity, template-directed incorporation of the ribonucleosides can be achieved.