DNA as a Catalyst and as a Sensor: Investigating the Structure of the Ty1 Retrotransposition Intermediate and the Utility of DNA -Based Biosensors

In vitro selection has been utilized to develop aptamers and aptazymes as components of small-molecule sensors. Aptamers have been selected for a range of targets from proteins to small-molecule ligands. Aptazymes have an aptamer domain that can allosterically control the catalysis of an attached nucleic acid enzyme. The targets for our sensors are mycotoxins, which are secondary metabolites of fungi. Mycotoxins have been found in crops during harvesting and storage. Consumption of mycotoxin-contaminated crops can lead to toxic effects in humans and animals, making it necessary to survey crops for these toxins. We have pursued two strategies to identify mycotoxin-sensing DNA aptamers and aptazymes, which will later be developed into on-site reporter systems. The first strategy was to implement direct selections for mycotoxin-dependent RNA-cleaving aptazymes. The second strategy was to conduct a selection for a mycotoxin aptamer that can later be appended to an RNA-cleaving deoxyribozyme through a communication module, which can be rationally designed or identified by in vitro selection. Aptamers with high affinities (K d <2 microM) have been identified for estradiol (E2) and zearalenone (ZEN). Conversion of the estradiol and zearalenone aptamers into sensors will utilize two different approaches: structure-switching signaling aptamers (switchamers) and aptazymes.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Pratico, Elizabeth D.

Contributors dc:contributor

• Silverman, Scott K.

• Chemistry, Biochemistry

Language dc:language

eng

Identifier

(MiAaPQ)AAI3337891

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/87896