Insights into Molecular Interactions Using Photoaffinity Labeling Coupled to Mass Spectrometry  

Résumé de la présentation:
Photoaffinity labeling coupled to mass spectrometry is a powerful approach for the characterization of interaction partners at the atomic level. These studies require careful optimization, including the strategic chemical labeling of one of the partners with an affinity purification tag and a photoreactive group. UV-irradiation of the photoprobe at a defined wavelength allows the formation of new covalent bonds with specific partners in close vicinity. Benzophenone (Bzp)-induced photo-crosslinking is commonly used for protein crosslinking. Some applications in the context of peptide interaction with biological membranes [1,2], membrane or soluble proteins [3,4] will be presented. Importantly, highly relevant information on molecular interactions can arise directly from the mass spectra when considering the specific photoreactivity of Bzp and side chemical reactions occuring in complex media. In this presentation, I will show you how MS-based approaches are highly valuable to answer complex biological questions.

References
[1] L. Bechtella et al., Structural Bases for the Involvement of Phosphatidylinositol-4,5-bisphosphate in the Internalization of the Cell-Penetrating Peptide Penetratin, ACS Chem. Biol. 17, (2022), 1427.
[2] L. Bechtella et al., Benzophenone Photoreactivity in a Lipid Bilayer To Probe Peptide/Membrane Interactions: Simple System, Complex Information, Anal. Chem. 91 (2019), 9102.
[3] E. Sachon et al., Isotope and affinity tags in photoreactive substance P analogues to identify the covalent linkage within the NK-1 receptor by MALDI-TOF analysis, Anal Chem. 75 (2003), 6536.
[4] S. Clavier et al., Photocross-linked peptide-protein complexes analysis: A comparative study of CID and ETD fragmentation modes, JASMS, 26 (2015), 1014.