Artificial ion channels formed by a synthetic cyclic peptide.
A new cyclic peptide 1 having an (LLLD)3 configuration pattern was designed that is capable of forming artificial transmembrane ion channels by self-assembly of planar peptide rings, with hydrophilic groups arrayed in the interior of the channel. Ion permeability in the presence of the synthetic peptide 1, cyclo[-Trp-Dap-Leu-D-Ala-Trp-Ser-Val-D-Ala-Trp-Ser-Ile-Gly-] (Dap: L-diaminopropionic acid), was observed in lipid bilayer membranes. The pH dependence of ionic conductance showed that the beta-amino group of Dap may play a role in the conductance of the peptide channels. Fourier-transform infrared and circular dichroism data imply that, in a membrane, a stack of cyclic peptides is formed in which the inter peptide H bonds form a kind of beta-structure analogous to that in the gramicidin A dimer and distinct from the H-bonding pattern of the beta-barrels.
Wang
D
D
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202-5122, USA.
Guo
L
L
Zhang
J
J
Jones
L R
LR
Chen
Z
Z
Pritchard
C
C
Roeske
R W
RW
D002942:Circular Dichroism; D004594:Electrophysiology; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D017434:Protein Structure, Tertiary; D017550:Spectroscopy, Fourier Transform Infrared
D007473:Ion Channels; D008051:Lipid Bilayers; D010456:Peptides, Cyclic