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Transmembrane Fluoride Transport by a Cyclic Azapeptide With Two β-Turns

Authors :
Miaomiao Zhang
Peimin Weng
Bailing Tang
Yueyang Zhang
Zhao Li
Yun-Bao Jiang
Zhixing Zhao
Xiao-Sheng Yan
Source :
Frontiers in Chemistry, Vol 8 (2021), Frontiers in Chemistry
Publication Year :
2021
Publisher :
Frontiers Media S.A., 2021.

Abstract

Diverse classes of anion transporters have been developed, most of which focus on the transmembrane chloride transport due to its significance in living systems. Fluoride transport has, to some extent, been overlooked despite the importance of fluoride channels in bacterial survival. Here, we report the design and synthesis of a cyclic azapeptide (a peptide-based N-amidothiourea, 1), as a transporter for fluoride transportation through a confined cavity that encapsulates fluoride, together with acyclic control compounds, the analogs 2 and 3. Cyclic receptor 1 exhibits more stable β-turn structures than the control compounds 2 and 3 and affords a confined cavity containing multiple inner –NH protons that serve as hydrogen bond donors to bind anions. It is noteworthy that the cyclic receptor 1 shows the capacity to selectively transport fluoride across a lipid bilayer on the basis of the osmotic and fluoride ion-selective electrode (ISE) assays, during which an electrogenic anion transport mechanism is found operative, whereas no transmembrane transport activity was found with 2 and 3, despite the fact that 2 and 3 are also able to bind fluoride via the thiourea moieties. These results demonstrate that the encapsulation of an anionic guest within a cyclic host compound is key to enhancing the anion transport activity and selectivity.

Details

Language :
English
ISSN :
22962646
Volume :
8
Database :
OpenAIRE
Journal :
Frontiers in Chemistry
Accession number :
edsair.doi.dedup.....75c1108d5da98bc9eaa2a2df81d72f75
Full Text :
https://doi.org/10.3389/fchem.2020.621323/full