We describe here a unique family of pore-forming anion transporting peptides possessing a single-amino-acid-derived peptidic backbone that is the shortest among natural and synthetic pore-forming peptides. These monopeptides with built-in H-bonding capacity self-assemble into an H-bonded 1D columnar structure, presenting three types of exteriorly arranged hydrophobic side chains that closely mimic the overall topology of an alpha-helix. Dynamic interactions among these side chains and membrane lipids proceed in a way likely similar to how a-helix bundle is formed. This subsequently enables oligomerization of these rod-like structures to form ring-shaped ensembles of varying sizes with a pore size of smaller than 1.0 nm in diameter but sufficiently large for transporting anions across the membrane. The intrinsic high modularity in the backbone further allows rapid tuning in side chains for combinatorial optimization of channel's ion-transport activity, culminating in the discovery of an exceptionally active anion-transporting monopeptide 6L10 with an EC50 of 0.10 mu M for nitrate anions.
A highly active and selective chalcogen bond-mediated perchlorate channel
Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or showhighselectivitytoward perchlorate anions are rare. In this work, we report on one such novel monopeptide-based transporter system, featuring both chalcogen bonds for highly efficient anion transport and high transport selectivitytoward ClO4− anions. Structurally, these monopeptide
Combinatorial Evolution of Fast-Conducting Highly Selective K<sup>+</sup>-Channels via Modularly Tunable Directional Assembly of Crown Ethers
作者:Changliang Ren、Jie Shen、Huaqiang Zeng
DOI:10.1021/jacs.7b04335
日期:2017.9.13
of highly efficient K+-selective channels. In our strategy, a highly robust supramolecular H-bonded 1D ensemble was used to order the appended crownethers in such a way that they roughly stack on top of each other to form a channel for facilitated ion transport across the membrane. Among 15 channels that all prefer K+ over Na+ ions, channel molecule 5F8 shows the most pronounced optimum for K+ while