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ORIGINAL RESEARCH article
Front. Chem.
Sec. Analytical Chemistry
Volume 12 - 2024 |
doi: 10.3389/fchem.2024.1438710
This article is part of the Research Topic Highly Efficient Selections and Applicable Utilizations of Aptamers as Molecular Recognition Elements View all articles
Pyoverdine Binding Aptamers and Label-Free Electrochemical Detection of Pseudomonads
Provisionally accepted- 1 Iowa State University, Ames, United States
- 2 Ames National laboratory (DOE), Ames, Iowa, United States
- 3 Independent researcher, Ames, United States
- 4 York University, Toronto, Ontario, Canada
Pyoverdines are iron-chelating siderophores employed by various pseudomonads to promote their growth in iron-limited environments, facilitating both beneficial and detrimental interactions with coinhabiting microbes or hosts, including plants and animals. The fluorescent pseudomonads produce fluorescent pyoverdines comprised of a conserved central chromophore and a unique strain-specific peptidic side chain produced by non-ribosomal peptide synthetases. Pyoverdine Pf5 (PVD-Pf5) is produced by Pseudomonas protegens Pf-5, a species known for supporting plant growth and its involvement in plant pathogen control. To develop a means of exploring the dynamics of P. protegens activity in soil and in the rhizosphere, we selected DNA aptamers that specifically recognize PVD-Pf5 with high affinities. Two selected aptamers with only 16% identity in sequence were examined for structure and function. We found evidence that both aptamers form structures in their apo-forms and one aptamer has structural features suggesting the presence of a G-quadruplex. Although their tertiary structures are predicted to be different, both aptamers bind the target PVD-Pf5 with similar affinities and do not bind other siderophores, including the related pyoverdine, pseudobactin, produced by Pseudomonas sp. B10. One aptamer binds the pyoverdine peptide component and may also interact with the chromophore. This aptamer was integrated into a nanoporous aluminum oxide biosensor and demonstrated to successfully detect PVD-Pf5 and not to detect other siderophores that do not bind to the aptamer when evaluated in solution. This sensor provides a future opportunity to track the locations of P. protegens around plant roots and to monitor PVD-Pf5 production and movement through the soil.
Keywords: NAAO, DNA Aptamer, SELEX, pyoverdine, Aptasensor
Received: 26 May 2024; Accepted: 12 Jul 2024.
Copyright: © 2024 Nilsen-Hamilton, Anisuzzaman, Singappuli-Arachchige, Alimoradi, Pogorelko, Banerjee, Kaiyum, Johnson and Shrotriya. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Marit Nilsen-Hamilton, Iowa State University, Ames, United States
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Dilini Singappuli-Arachchige
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