Tautomerism of a backbone protonated peptide revealed by soft X-ray action spectroscopy
Citation Link: https://doi.org/10.15480/882.15103
Publikationstyp
Journal Article
Date Issued
2025-04-04
Sprache
English
TORE-DOI
Volume
27
Issue
16
Start Page
8320
End Page
8326
Citation
Physical Chemistry Chemical Physics 27 (16): 8320-8326 (2025)
Publisher DOI
Scopus ID
Publisher
Royal Society of Chemistry (RSC)
The structure and reactivity of peptides can be influenced by their protonation state. Notably, protonation of the backbone can induce structural changes, such as tautomerism, shifting from the stable keto form to the enol form. This phenomenon, particularly in the backbone protonated peptide acetyl-pentaglycine, was examined using a combination of soft X-ray action spectroscopy at the nitrogen K-edge and theoretical calculations based on density functional theory (DFT). We identified a resonance at 400 eV that can be clearly attributed to π*(C=N) transitions, linked exclusively to the enol form, as no keto form structures could replicate this resonance. These findings enhanced our understanding of the effect of protonation on the structure of peptides and could be employed for future dynamic studies.
DDC Class
572: Biochemistry
541: Physical; Theoretical
539: Matter; Molecular Physics; Atomic and Nuclear physics; Radiation; Quantum Physics
519: Applied Mathematics, Probabilities
Publication version
publishedVersion