A Synthetic Transmembrane Channel Active in Lipid Bilayers

Abstract

tains 15 L-leucine residues it is both sufficiently hydrophobic to be incorporated in lipid bilayers[41 and favors u-helical conformation. ['] In this form the crown ether rings in I are perfectly aligned (Figure 1). Herein we present the results of studies on the conformation of 1 and its incorporation in planar C.

Recent synthetic ion channels and pores

“…The cylindrical self-assembly of rigid-rod b-barrel pores 72-77 is preorganized by the non-planarity of p-octiphenyl Figure 11. Dimeric and oligomeric steroids that may act as carriers (54-59)-folding like umbrellas around hydrophilic guests-or as barrel-stave-like channels formed by two covalent dimers spanning one leaflet each (60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70)(71). staves in octapeptide-p-octiphenyl monomers 72 m -77 m (Fig.…”

Regulation of Lipid Bilayer Ion Permeability by Antibacterial Polymethyloxazoline‐Polyethyleneimine Copolymers

“…For hydrophobically‐modified polyacrylic acids [41] and poly(2‐ethylacrylic acid), [42] channel‐like behavior was one of several reported activities. Some cyclic and oligomeric poly(ethylene glycol) derivatives [40,43–45] and similar ethers [46,47] also display such behavior. Those are good ion coordinating molecules bearing donor heteroatoms separated with two carbon spacers.…”

Crown ether helical peptides are preferentially inserted in lipid bilayers as a transmembrane ion channels

“…Oriented CD (OCD) on macroscopically aligned samples is ideally suited to determine the membrane orientation of α‐helical peptides, especially whether they orient parallel (I‐state) or perpendicular (S‐state) to the bilayer normal, and at the same time the secondary structure of the peptide can be monitored (Figure ) . With regard to the crown ether peptides, it has been shown that they tend to fold as α‐helices and interact with membranes . However, the polyethylene glycol (PEG)‐based crown ethers are intrinsically amphiphilic and known to be soluble both in polar and unpolar solvents.…”

“…[14][15][16] With regard to the crown ether peptides, it has been shown that they tend to fold as a-helices and interact with membranes. 17 However, the polyethylene glycol (PEG)-based crown ethers are intrinsically amphiphilic and known to be soluble both in polar and unpolar solvents. Therefore, it is unknown whether these functional groups prefer to face the aqueous layer on the membrane surface (i.e., with the peptide in an S-state), or whether they would rather immerse into the hydrophobic bilayer interior (in an I-state).…”