Beyond Aquaporins: Recent Developments in Artificial Water Channels

Abstract

A molecular scale understanding of the fast and selective water transport in biological water channels, aquaporins (AQPs), has inspired attempts to mimic its performance in synthetic structures. These synthetic structures, referred to as artificial water channels (AWCs), present several advantages over AQPs in applications. After over a decade of efforts, the unique transport properties of AQPs have been reproduced in AWCs. Further, recent developments have shown that the performance of benchmark AQP channels can be exceeded by new AWC designs using novel features not seen in biology. In this Perspective, we provide a brief overview of recent AWC developments, and share our perspective on forward-looking AWC research.

Visualizing Water Monomers and Chiral OH–(H2O) Complexes Infiltrated in a Macroscopic Hydrophobic Teflon Matrix

“…On the other hand, a recent report illustrated that nanochannels with a densely fluorous interior surface exhibit ultrafast water permeability (over aquaporins by a factor of up to ∼10 3 ) and negligible chloride ion permeation . The authors attributed this very surprising result to the breakage of water clusters into smaller pieces by the electrostatic interactions between fluorine and water. , This high permeability value was almost equal to the limit of the diffusion rate of ideal noninteracting molecules predicted using kinetic theory at thermodynamic equilibrium. , Therefore, it is anticipated that it should form water monomers within channels rather than smaller clusters or single file water “wires”. Similar to the nanochannels, the water that infiltrated in the Teflon matrix is likely in a monomer state.…”

Beyond Natural Channel Proteins: Recent Advances in Fluorinated Nanochannels

“…Thus, channel proteins that span the cellular membranes and possess a subnanometer-sized pore are essential for their transmembrane permeation . Inspired by the structures and functions of such channel proteins found in nature, synthetic chemists have developed their synthetic analogues by mimicking their structural features over the past 40 years. − Ion permeation through synthetic channels is considered important for therapeutic purposes in ion-channel-related diseases (channelopathies), and water permeation through synthetic channels is attracting attention for its potential application in industrial water desalination …”