Journal Article

PUBDB-2025-04829

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png X-ray absorption spectroscopy reveals charge transfer in π-stacked aromatic amino acids

Ortiz-Mahecha, C. ; Schwob, L.XFEL.EU*DESY* ; Leroux, J.CFEL*Extern* ; Bari, S.DESY* ; Meissner, R. (Corresponding author)Extern* ; Bande, A. (Corresponding author)

2025
RSC Publ. Cambridge

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Please use a persistent id in citations: doi:10.1039/D4CP04615C  doi:10.3204/PUBDB-2025-04829

Abstract: X-ray absorption spectroscopy (XAS) and quantum mechanical calculations bear great potential to unravel π stacking side-chain interaction properties and structure in, e.g., proteins. However, core-excited state calculations for proteins and their associated interpretation for π–π interactions are challenging due to the complexity of the non-covalent interactions involved. A theoretical analysis is developed to decompose the core-to-valence transitions into their atomic contributions in order to characterize the π stacking of aromatic amino acids as a function of their non-covalent distance change. Three models were studied as a non-covalent mixed dimers of the phenylalanine, tyrosine and tryptophan amino acids. We found that there are carbon 1s → π* charge transfer transitions associated with the non-covalently paired aromatic amino acids through their side chains. The atomic-centered contributions to the electronic transition density quantify the excited state charge transfer of the pairing amino acid models, highlighting the π stacking interactions between their aromatic side chains.

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Contributing Institute(s):

1. Biomoleküle in Gasphase (FS-BIG)

Research Program(s):

1. 633 - Life Sciences – Building Blocks of Life: Structure and Function (POF4-633) (POF4-633)
2. DFG project G:(GEPRIS)390715994 - EXC 2056: CUI: Tiefe Einblicke in Materie (390715994) (390715994)
3. DFG project G:(GEPRIS)217133147 - SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen (217133147) (217133147)
4. HIDSS-0002 - DASHH: Data Science in Hamburg - Helmholtz Graduate School for the Structure of Matter (2019_IVF-HIDSS-0002) (2019_IVF-HIDSS-0002)

Experiment(s):

1. No specific instrument
2. PETRA Beamline P24 (PETRA III)

Appears in the scientific report 2025

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF < 5 ; JCR ; National-Konsortium ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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