Highly Selective Artificial Potassium Ion Channels Constructed from Pore‐Containing Helical Oligomers

Single-stranded DNA designed lipophilic G-quadruplexes as transmembrane channels for switchable potassium transport

G-quadruplex single-stranded DNA was modified lipophilically and developed as a biomimetic ion channel for selective and switchable K⁺ transport.

Crystal structure of a protein–aromatic foldamer composite: macromolecular chiral resolution

A protein–foldamer crystal structure illustrates protein assembly by a sulfonated aromatic oligoamide, and chiral resolution of the foldamer helix handedness.

Structure-Driven Selection of Adaptive Transmembrane Na+ Carriers or K+ Channels

Self-assembled alkyl-ureido-benzo-15-crown-5-ethers are selective ionophores for K⁺ cations, which are preferred to Na⁺ cations. The transport mechanism is determined by the optimal coordination rather than classical dimensional compatibility between the crown ether hole and the cation diameter. Herein, we demonstrate that systematic changes of the structure lead to unexpected modifications in the cation-transport activity and suffice to produce adaptive selection. We show that the main contribution to performance arises from optimal constraints on the conformational freedom, which are determined by the binding macrocycles, the nature of the hydrogen-bonding groups, and the hydrophobic tails. Simple changes to the flexible 15-crown-5-ether lead to selective carriers for Na⁺ . Hydrophobic stabilization of the channels through mutual interactions between lipids and variable hydrophobic tails appears to be an important cause of increased activity. Oppositely, restricted translocation is achieved when constrained hydrogen-bonded macrocyclic relays are less dynamic in a pore superstructure.

Artificial water channels: inspiration, progress, and challenges

Developing bioinspired artificial water channels may lead to the next-generation filtration membranes with ultra-high pore density and exclusive water permeability.