The gramicidin ion channel: A model membrane protein

Abstract

The linear peptide gramicidin forms prototypical ion channels specific for monovalent cations and has been extensively used to study the organization, dynamics and function of membrane-spanning channels. In recent times, the availability of crystal structures of complex ion channels has challenged the role of gramicidin as a model membrane protein and ion channel. This review focuses on the suitability of gramicidin as a model membrane protein in general, and the information gained from gramicidin to understand lipid-protein interactions in particular. Special emphasis is given to the role and orientation of tryptophan residues in channel structure and function and recent spectroscopic approaches that have highlighted the organization and dynamics of the channel in membrane and membrane-mimetic media.

A Simple Method for Ion Channel Recordings Using Fine Gold Electrode

“…It is known that for gramicidin channels to show activity, gramicidin must form a tandem dimer in the membrane. 19 In addition, gramicidin channel activity indicates removal of the organic solvent and the formation of a sufficiently thin membrane. Figure 2 further demonstrates that we can quickly repeat current measurements using the single electrode.…”

A Comparative Study of Stress-mediated Immunological Functions with the Adjuvanticity of Alum

“…These differ in their properties, they act as stress agents that reactivate quiescent HSV-1 viral genomes (22) and they have been used in clinical practice. Gramicidine is an antibiotic, which functions as an ionophore, penetrating cell membranes, causing K ϩ efflux (23) and is effective against Gram-positive bacteria, fungi, protozoa, and viruses (24). It has been used clinically as an ophthalmic antimicrobial (Neoporin) and for genital ulcers (25).…”

Bioelectronic Light‐Gated Transistors with Biologically Tunable Performance

“…Nigericin, a transmembrane carrier that catalyzes an electroneutral K + /H + exchange across the lipid bilayer, [ 23 ] relieves the proton gradient, but preserves the electric fi eld gradient. Finally, gramicidin A (gramA), a peptide that forms a passive channel in the membrane, allows fast nonspecifi c ion leakage [ 24 ] and neutralizes both of these gradients.…”