Zamora-Carreras, HéctorMaestro García-Donas, María BeatrizStrandberg, EricUlrich, AnneSanz, JesúsJiménez, María Angeles2024-01-232024-01-112024-01-232015Zamora‐Carreras, Héctor, et al. «Micelle‐Triggered β‐Hairpin to α‐Helix Transition in a 14‐Residue Peptide from a Choline‐Binding Repeat of the Pneumococcal Autolysin LytA». Chemistry – A European Journal, vol. 21, n.o 22, mayo de 2015, pp. 8076-89. https://doi.org/10.1002/chem.201500447.0947-653910.1002/chem.201500447https://hdl.handle.net/20.500.14352/92617.2Choline-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://doi.org/10.1002/chem.201500447open access577.1MicellesProtein foldingProtein structuresStructural biologyStructural elucidationBioquímica (Química)2403 Bioquímica