A K⁺-selective channel with a record-high K⁺/Na⁺selectivity of 20.1

Abstract

Centered around a single phenylalanine residue amidated to have a 15-crown-5 unit at its N-terminus and a straight alkyl chain at its C-terminus, a simple tuning in alkyl chain length...

Sulfur‐Containing Foldamer‐Based Artificial Lithium Channels

“…Through the investigation of four artificial K + ‐selective channels 5Fn ( n =8–14), [4h] we recently found an interesting correlation between the binding constant ( K a ) and transport selectivity. Having K + /Na + transport selectivity factors of 9.8–20.1, 5Fn all display a higher K a (Na + ) value that is 3–5 times that of K a (K + ).…”

Artificial transmembrane potassium transporters: designs, functions, mechanisms and applications

“…Nevertheless, despite these efforts, astonishingly high ion transport selectivity manifested by natural potassium channels still presents a daunting challenge to the field of APTs. Specifically, from 2017 to the present, the K + /Na + selectivity factor has gradually increased from 9.8 15 to 20.1 16,17 based on single channel current measurement with KCl and NaCl at 1 M. Considering a >1000-fold discrimination by nature, these values by APTs are very moderate, indicating great room for future development.…”

“…Additionally, Zeng et al investigated the effect of extending the side chain length. 67 As the side chain length increases, the binding ability of the 15-crown-5 moiety to K + also increases, leading to a decrease in Ka(Na + )/Ka(K + ). The resulting channel 5F12 demonstrates excellent selectivity for K + /Na + ions with a selectivity ratio of 20.1 (Fig.…”

Selective confinement of potassium, rubidium, or caesium ions in a non-covalent hydroxyproline octamer cage stabilized by cis-hydroxyl locks

“…Thus, the structure of C4LP8-K-1 is also expected to be cross-linked in some way to form biocompatible membrane transporters with high K + /Na + selectivity. 27 On the other hand, for the molecule of trans-4-hydroxy-Lproline, the calculated most stable isomer of [(T4LP) 8 + K] 1+ is identified as T4LP-8-K-1 (Fig. S12 and Table 1, ESI †).…”

“…Thus, the structure of C4LP8-K-1 is also expected to be cross-linked in some way to form biocompatible membrane transporters with high K + /Na + selectivity. 27…”