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Updated: Jul 30, 2026

Gramicidin-based Fluorescence Assay; for Determining Small Molecules Potential for Modifying Lipid Bilayer Properties
Published on: October 13, 2010
Size-exclusion high-performance liquid chromatography in the study of the autoassociating antibiotic gramicidin A in
Maria Carmen Bañó1, David Salom, Concepción Abad
1Departament de Bioquímica i Biologia Molecular, Universitat de València, C/ Doctor Moliner 50, E-46100 Burjassot, Valencia, Spain.
Abstract:
Gramicidin A (gA) is a polypeptide antibiotic which forms dimeric channels specific for monovalent cations in biological membranes. It is a polymorphic molecule that adopts several different conformations, double-stranded (ds) helical dimers (pore conformation) and single-stranded beta-helical dimers (channel conformation). This study investigated the conformational adaptability of gramicidin A when incorporated into micelles as membrane-mimetic model system. Taking advantage of our reported, versatile, size-exclusion high-performance liquid chromatography (SE-HPLC) strategy that allows the separation of double-stranded dimers and monomers, we have quantitatively characterized the conformational transition undergone by the peptide in the micellar milieu. The importance of both hydrophobic/hydrophilic moieties of the amphipaths in the stabilization of concrete conformational species is demonstrated using detergents with different hydrocarbon chain length and/or polar head. SE-HPLC is a valuable, rapid, accurate technique for the structural characterization of hydrophobic autoassociating peptides that work in lipid environments such as biological membranes.
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