Anionophores are molecules that can transport ions across membranes. Several structural design criteria must be met for anionophores to be highly active. Fluorinated anionophores are usually more potent than their non-fluorinated analogues due to their higher lipophilicity and increased affinity for anions. Clear structure-activity relationships have been described for small and relatively simple anionophores. However, such studies are more challenging for large and macrocyclic anionophores, as their preparation is usually more complicated, limiting the number of compounds tested in anion transport studies. Here we present a series of twelve macrocyclic bambusuril anion transporters to investigate how variations in fluorinated substituents affect their transport properties. Measurements of Cl-/HCO3- antiport activities in liposomes revealed links between parameters such as lipophilicity or substituent polarity and transport activity. For some bambusurils, an unusually large effect of the presence of cholesterol in the membrane on transport activity was found. Further studies showed that for very potent anion receptors, such as the bambusurils described here, the binding selectivity towards anions becomes more important than the absolute binding affinity to anions when considering anion exchange across the membrane.

• Publikační typ
• časopisecké články MeSH

Artificial anion transporters offer a potential way to treat deficiencies in cellular anion transport of genetic origins. In contrast to the large variety of mobile anion carriers and self-assembled anion channels reported, unimolecular anion channels are less investigated. Herein, we present a unique example of a unimolecular anion channel based on a bambusuril (BU) macrocycle, a well-established anion receptor. The BU structure was expanded by appending various bile acid residues allowing a single molecule to span the membrane. Chloride transport mediated by BUs through lipid bilayers was investigated in liposomes and these studies revealed a surprisingly high dependence of the anion transport activity on the cholesterol content in the liposomal membrane.

• Klíčová slova
• Anion Channels, Anion transport, Bambusurils, Macrocycles, Supramolecular Chemistry,
• MeSH
• anionty chemie   metabolismus   MeSH
• cholesterol * chemie   metabolismus   MeSH
• iontový transport MeSH
• lipidové dvojvrstvy chemie   metabolismus   MeSH
• liposomy chemie   metabolismus   MeSH
• žlučové kyseliny a soli * chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anionty MeSH
• cholesterol * MeSH
• lipidové dvojvrstvy MeSH
• liposomy MeSH
• žlučové kyseliny a soli * MeSH

Stimuli-responsive transmembrane ion transport has become a prominent area of research due to its fundamental importance in cellular processes and potential therapeutic applications. Commonly used stimuli include pH, light, and reduction or oxidation agents. This paper presents the use of dynamic covalent chemistry to activate and modulate the transmembrane transport of chloride in liposomes. An active chloride transporter was obtained in situ within the lipid bilayer by dynamic azine metathesis. The transport activity was further tuned by changing the structure of the added azines, while the dynamic covalent chemistry could be activated by lowering the pH. This dynamic covalent chemistry opens a new approach towards controlling transmembrane transport.

• Publikační typ
• časopisecké články MeSH