PAS-Domain Protein Orientation at a Polyelectrolyte Surface Revealed by Infrared Nanospectroscopy, Chiral Vibrational Spectroscopy, and Molecular Dynamics Simulations
is a model PAS-domain protein involved in negative phototaxis, yet its signaling partner remains unidentified. Here, we present a method to resolve protein orientations in PAS-domain signaling by combining nano-FTIR and chiral vibrational sum-frequency generation (VSFG) spectroscopy with molecular dynamics simulations and VSFG spectral calculations. As a demonstration, we used a charged homopolypeptide, poly-l-lysine (PLL), as a surrogate binding surface to probe PYP docking. We found that PYP adopts a preferred interfacial orientation driven primarily by dipole-dipole interactions, despite its water-soluble, i.e., cytoplasmic nature. Remarkably, the inferred interaction surface and orientation closely match those observed in PYP homodimers and in a CNBh-PAS heterodimer. This methodology enables in situ determination of protein orientational preferences during protein-protein interactions and may facilitate identification of binding partners in PAS-domain signaling pathways.
Authors
- Zoltán Násztor (ORCID: https://orcid.org/0000-0002-0895-6985)
- Zsuzsanna Heiner (ORCID: https://orcid.org/0000-0002-9458-9164)
- Szilvia Krekic (ORCID: https://orcid.org/0000-0003-4972-722X)
- János Horváth (ORCID: https://orcid.org/0000-0003-0147-4518)
- Mark Mero (ORCID: https://orcid.org/0000-0001-5454-583X)
- Ferenc Bogár (ORCID: https://orcid.org/0000-0002-0611-1452)
- Alexander Veber (ORCID: https://orcid.org/0000-0003-4894-5639)
- András Dér (ORCID: https://orcid.org/0000-0001-6112-884X)
- Ljiljana Puškar (ORCID: https://orcid.org/0000-0002-8191-7472)
- Montserrat Román Quintero (ORCID: https://orcid.org/0009-0002-1576-6909)
Institutions
- University of Szeged (HU)
- HUN-REN Szegedi Biológiai Kutatóközpont (HU)
- Helmholtz-Zentrum Berlin für Materialien und Energie (DE)
- Humboldt-Universität zu Berlin (DE)
- Systems Dynamics (United States) (US)
- BioMimetic Systems (United States) (US)
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy (DE)
Publication Details
- Journal
- Biomacromolecules
- Published
- 2026-04-30
- DOI
- https://doi.org/10.1021/acs.biomac.5c02743
- Primary Topic
- Spectroscopy and Quantum Chemical Studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Deutscher Akademischer Austauschdienst
- Deutsche Forschungsgemeinschaft
- Tempus Közalapítvány
- Horizon 2020
- Nemzeti Kutatási, Fejlesztési és Innovaciós Alap
- German Academic Exchange Service