1.D.176.  The Hydroxyl-rich Cholesterol-Flexible Alkyl Chain-Crown Ether  Ion Transporter (H-CIT-A-CE) Family 

The ion-fishing mechanism underlying ion transport across membranes mediated by an artificial ion transporter, composed of a hydroxyl-rich cholesterol group, a flexible alkyl chain, and a crown ether, have been investigated (Miao et al. 2022). The transporter can spontaneously insert into the membrane and switch between the folded (U-shaped) and extended (I-shaped) conformations. The free-energy profile associated with the conformational transition indicates that compared with the U-shaped conformation of the transporter, the I-shaped one is thermodynamically more favorable. The free-energy profiles describing ion translocation reveal the transporter capturing the ion in the U-shape on one side of the membrane and releasing it in the I-shape on the other side.  This constitutes a key way for the highly efficient transport of K+ ions. This presents a rigorous and rational framework to decipher the detailed ion-fishing mechanism of transmembrane ion transport with exceptionally high activity (Miao et al. 2022).

This family belongs to the Crown Ether Artificial Ion Transporter Superfamily.



Miao, M., X. Shao, and W. Cai. (2022). Conformational Change from U- to I-Shape of Ion Transporters Facilitates K Transport across Lipid Bilayers. J Phys Chem B 126: 1520-1528.