How Far Can a Sodium Ion Travel within a Lipid Bilayer?

Abstract

Analogues of a synthetic ion channel made from a helical peptide were used to study the mechanism of cation translocation within bilayer membranes. Derivatives bearing two, three, four, and six crown ethers used as ion relays were synthesized, and their transport abilities across lipid bilayers were measured. The results showed that the maximum distance a sodium ion is permitted to travel between two binding sites within a lipid bilayer environment is 11 Å.

Antimicrobial Peptides from the Aurein Family Form Ion‐Selective Pores in Bacillus subtilis

“…[17] Phosphatidylglycerol and phosphatidylethanolamine are the most abundant phospholipids in B. subtilis. [18] In order to imitate the phospholipid head group composition of the B. subtilis membrane, 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol)/1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPG/DPPE) vesicles were used to assess influx of potassium and sodium ( Figure 7).…”

“…In vitro ion translocation measurements: The translocation experiments were performed by the method of Otis et al, [17] but with DPPG/DPPE (88:12; Avanti Polar Lipids, Alabaster, AL) instead of phosphatidylcholine (PC) lipid. Briefly, DPPG/DPPE vesicles were prepared by drying DPPG (420 mL) and DPPE (50 mL, both at 25 mg mL…”

Highly Selective Artificial Cholesteryl Crown Ether K+‐Channels

“…[4] Biomimetic approaches have been used to develop artificial supramolecular channels with the hope to reach the high selectivity of the KcsA channel. [5][6][7] Barrel-stave systems, [8] G-quadruplex, [9] lariat crown ethers, [10] hydraphiles [11] or peptide-appended crownethers [12,13] have been intensively used to construct ion-channels for selective ionic translocation. We are interested in the possibility to selforganize heteroditopic ureido crown ethers through H-bonding for suitable membrane ion channel transport functions.…”

Transmembrane anion transport mediated by halogen-bond donors

“…In biology, anion transport is usually achieved by very large transmembrane proteins with multiple anion-binding sites for cooperative transport at high selectivity and speed. The creation of synthetic anion transporters has attracted attention owing to possible applications in the materials sciences (for example, as sensors and photosystems) and in medicine (possible treatment of channelopathies, for example, cystic fibrosis) [1][2][3][4][5][6][7][8][9][10][11][12][13] . Anion transport is usually achieved by hydrogen bonding and ion pairing.…”