Zamora-Carreras, H.Maestro García-Donas, María BeatrizStrandberg, E.Ulrich, A. S.Sanz, J. M.Jiménez, M. A.2024-01-112024-01-112015-05-260947-653910.1002/chem.201500447https://hdl.handle.net/20.500.14352/92617Choline-binding modules (CBMs) have a ββ-solenoid structure composed of choline-binding repeats (CBR), which consist of a β-hairpin followed by a short linker. To find minimal peptides that are able to maintain the CBR native structure and to evaluate their remaining choline-binding ability, we have analysed the third β-hairpin of the CBM from the pneumococcal LytA autolysin. Circular dichroism and NMR data reveal that this peptide forms a highly stable native-like β-hairpin both in aqueous solution and in the presence of trifluoroethanol, but, strikingly, the peptide structure is a stable amphipathic α-helix in both zwitterionic (dodecylphosphocholine) and anionic (sodium dodecylsulfate) detergent micelles, as well as in small unilamellar vesicles. This β-hairpin to α-helix conversion is reversible. Given that the β-hairpin and α-helix differ greatly in the distribution of hydrophobic and hydrophilic side chains, we propose that the amphipathicity is a requirement for a peptide structure to interact and to be stable in micelles or lipid vesicles. To our knowledge, this "chameleonic" behaviour is the only described case of a micelle-induced structural transition between two ordered peptide structures.engAttribution-NonCommercial 4.0 Internationalhttp://creativecommons.org/licenses/by-nc/4.0/journal article1521-3765https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/chem.201500447open access577.1micellesprotein foldingprotein structuresstructural biologystructural elucidationBioquímica (Química)2403 Bioquímica