Conformational Shift of a β‐Hairpin Peptide upon Complex Formation with an Oligo–proline Peptide Studied by Mass Spectrometry. Issue 13 (19th August 2016)

• Record Type: Journal Article
• Authors: Kölbel, Knut; Warnke, Stephan; Seo, Jongcheol; von Helden, Gert; Moretti, Rocco; Meiler, Jens; Pagel, Kevin; Sinz, Andrea
• Is Part Of: ChemistrySelect. Volume 1:Issue 13(2016)
• Page Start: 3651
• Page End: 3656
• Publication Date: 2016-08-19
• Subjects: cross-linking -- ion mobility -- mass spectrometry -- peptide secondary structure -- Rosetta modelling workflow; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201600934
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: 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. Abstract : The analysis of protein 3D‐structures by cross‐linking and high‐resolution mass spectrometry might well be dubbed as is "putting needles into the haystack" in analogy to measuring "frozen turkeys" or "flying elephants" for X‐ray crystallography and native MS. In the study presented here, we demonstrate the application of photo‐activated cross‐linking to study the structure of a β‐hairpin as well as to discriminate between coexisting conformations and binding mechanisms.