Description:	We recently reported that some adenosine binding aptamers can also bind caffeine and theophylline with around 20-fold lower affinities. This discovery led to the current work to examine the cross-binding of adenosine to theophylline aptamers. For the DNA aptamer for theophylline, cross-binding to adenosine was observed, and the affinity was 18 to 38-fold lower for adenosine based on assays using isothermal titration calorimetry and ThT fluorescence spectroscopy. The binding complexes were characterized using NMR spectroscopy, and both adenosine and theophylline showed an overall similar binding structure to the DNA theophylline aptamer, although small differences were also observed. In contrast, the RNA aptamer did not show binding to adenosine, although both aptamers have very similar relative selectivity for various methylxanthines including caffeine. After a negative selection, a few new aptamers with completely different primary sequences for theophylline were obtained and they did not show binding to adenosine. Thus, there are many ways for aptamers to bind theophylline and some can have cross-binding to adenosine. In biology, theophylline, caffeine, and adenosine can bind to the same protein receptors to regulate sleep, and their binding to the same DNA motifs may suggest an early role of nucleic acids in similar regulatory functions.
Authors:	Huang, Po-Jung Jimmy; University of Waterloo; 0000-0003-3436-9968 Li, Albert Zehan; University of Waterloo; 0009-0008-6294-5073 Dieckmann, Thorsten; University of Waterloo Liu, Juewen; University of Waterloo; 0000-0001-5918-9336
Keywords:	DNA SELEX Aptamer Adenosine Theophylline
Field of Research:	Biological sciences > Biochemistry > Analytical biochemistry
Publication Date:	2023-10-20
Publisher:	Federated Research Data Repository / dépôt fédéré de données de recherche
Funder:	Natural Sciences and Engineering Research Council Canada Excellence Research Chairs; Global Water Future project
URI:	https://doi.org/10.20383/103.0826
Related Identifiers:	This dataset is cited by https://doi.org/10.1002/cbic.202300566
Geographic Coverage:	Place Name University of Waterloo City Waterloo Province / Province / Territory Ontario Territory   Country Canada
Appears in Collections:	Water Institute