Site-selectivity of Phl p 5 Modifications and their Influence on the Inflammatory Potential
- Objective: Resolve how peroxynitrite and O3/NO2 reshape tyrosine chemistry in Phl p 5 and modulate TLR4 activation. Design: Recombinant Phl p 5 underwent defined ONOO−:Y titrations and O3/NO2 exposures. ND, HOY-D, and dityrosine cross-links were quantified; modified residues were assigned; TLR4 responses were benchmarked to native.
Key results: Y285 exhibited highest susceptibility across pathways; Y236 remained unmodified. ND peaked at ONOO−:Y = 3:1 and at O3/NO2 = 10/200 ppb. The strongest hydroxylation arose with 200 ppb O3, predominating at Y112 and Y285. Cross-linking patterns diverged: ONOO− increased domain-1 connectivity while suppressing head/tail links; NO2 shifted cross-linking toward head/tail positions.
Biological effect: ONOO− did not raise TLR4 activity, whereas 200 ppb O3 produced a ~6% increase. Conclusion: Phl p 5 modification is residue- and chemistry-specific. Ozone-driven hydroxylation correlates with higher TLR4 signaling, while peroxynitrite-drivenObjective: Resolve how peroxynitrite and O3/NO2 reshape tyrosine chemistry in Phl p 5 and modulate TLR4 activation. Design: Recombinant Phl p 5 underwent defined ONOO−:Y titrations and O3/NO2 exposures. ND, HOY-D, and dityrosine cross-links were quantified; modified residues were assigned; TLR4 responses were benchmarked to native.
Key results: Y285 exhibited highest susceptibility across pathways; Y236 remained unmodified. ND peaked at ONOO−:Y = 3:1 and at O3/NO2 = 10/200 ppb. The strongest hydroxylation arose with 200 ppb O3, predominating at Y112 and Y285. Cross-linking patterns diverged: ONOO− increased domain-1 connectivity while suppressing head/tail links; NO2 shifted cross-linking toward head/tail positions.
Biological effect: ONOO− did not raise TLR4 activity, whereas 200 ppb O3 produced a ~6% increase. Conclusion: Phl p 5 modification is residue- and chemistry-specific. Ozone-driven hydroxylation correlates with higher TLR4 signaling, while peroxynitrite-driven nitration/cross-linking leaves TLR4 unchanged. These relationships pinpoint reactive hotspots and suggest exposure-dependent mechanisms in pollutant-enhanced allergenicity.…


| Autor*innen: | Nadine Bothen |
|---|---|
| Koautor*innen: | Anna Lena Leifke, Michael G. WellerORCiD, Ulrich PöschlORCiD, Janine FröhlichORCiD |
| Dokumenttyp: | Posterpräsentation |
| Veröffentlichungsform: | Präsentation |
| Sprache: | Englisch |
| Jahr der Erstveröffentlichung: | 2025 |
| Organisationseinheit der BAM: | 1 Analytische Chemie; Referenzmaterialien |
| 1 Analytische Chemie; Referenzmaterialien / 1.5 Proteinanalytik | |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Sanitär- und Kommunaltechnik; Umwelttechnik |
| Freie Schlagwörter: | Allergen; Allergy; Grass pollen; Inflammation; Nitrogen oxides; Ozone; TLR4; Tyrosine modification |
| Themenfelder/Aktivitätsfelder der BAM: | Umwelt |
| Umwelt / Umwelt-Material-Interaktionen | |
| Veranstaltung: | European Aerosol Conferences (EAC) |
| Veranstaltungsort: | Lecce, Italy |
| Beginndatum der Veranstaltung: | 31.08.2025 |
| Enddatum der Veranstaltung: | 05.09.2025 |
| Zugehöriger Identifikator: | https://eac2025.iasaerosol.it |
| Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
| Datum der Freischaltung: | 10.10.2025 |
| Referierte Publikation: | Nein |

