Description:
<jats:title>Abstract</jats:title><jats:p>So‐called super‐secondary structures such as the β‐hairpin, studied here, form an intermediate hierarchy between secondary and tertiary structures of proteins. Their sequence‐derived ‘pure’ peptide backbone conformation is combined with ‘remote’ interstrand or interresidue contacts reminiscent of the 3D‐structure of full‐length proteins. This renders them ideally suited for studying potential nucleation sites of protein folding reactions as well as intermolecular interactions. But β‐hairpins do not merely serve as model systems; their unique structure characteristics warrant a central role in structural studies on their own. In this study we applied photo cross‐linking in combination with high‐resolution mass spectrometry and computational modeling as well as with ion mobility‐mass spectrometry to elucidate these structural properties. Using variants of a known β‐hairpin representative, the so‐called trpzip peptide and its ligands, we found evidence for a conformational transition of the β‐hairpin and its impact on ligand binding.</jats:p>