%0 Journal Article
%A Mudryk, Karen
%A Lee, Chin
%A Tomaník, Lukáš
%A Malerz, Sebastian
%A Trinter, Florian
%A Hergenhahn, Uwe
%A Neumark, Daniel M.
%A Slavicek, Petr
%A Bradforth, Stephen
%A Winter, Bernd
%T How Does Mg<sup>2+</sup><sub>(aq)</sub> Interact with ATP<sub>(aq)</sub>? Biomolecular Structure through the Lens of Liquid-Jet Photoemission Spectroscopy
%J Journal of the American Chemical Society
%V 146
%N 23
%@ 0002-7863
%C Washington, DC
%I ACS Publications
%M PUBDB-2024-04728
%P 16062-16075
%D 2024
%Z Open Access
%X Liquid-jet photoemission spectroscopy (LJ-PES) allows for a direct probing of electronic structure in aqueous solutions. We show the applicability of the approach to biomolecules in a complex environment, exploring site-specific information on the interaction of adenosine triphosphate in the aqueous phase (ATP<sub>(aq)</sub>) with magnesium (Mg<sup>2+</sup><sub>(aq)</sub>), highlighting the synergy brought about by the simultaneous analysis of different regions in the photoelectron spectrum. In particular, we demonstrate intermolecular Coulombic decay (ICD) spectroscopy as a new and powerful addition to the arsenal of techniques for biomolecular structure investigation. We apply LJ-PES assisted by electronic-structure calculations to study ATP<sub>(aq)</sub> solutions with and without dissolved Mg<sup>2+</sup>. Valence photoelectron data reveal spectral changes in the phosphate and adenine features of ATP<sub>(aq)</sub> due to interactions with the divalent cation. Chemical shifts in Mg 2p, Mg 2s, P 2p, and P 2s core-level spectra as a function of the Mg<sup>2+</sup>/ATP concentration ratio are correlated to the formation of [Mg(ATP) <sub>2</sub>]<sup>6−</sup><sub>(aq)</sub>, [MgATP]<sup>2−</sup><sub>(aq)</sub>, and [Mg<sub>2</sub>ATP]<sub>(aq)</sub> complexes, demonstrating the element sensitivity of the technique to Mg<sup>2+</sup>–phosphate interactions. The most direct probe of the intermolecular interactions between ATP<sub>(aq)</sub> and Mg<sup>2+</sup><sub>(aq)</sub> is delivered by the emerging ICD electrons following ionization of Mg 1s electrons. ICD spectra are shown to sensitively probe ligand exchange in the Mg<sup>2+</sup>–ATP<sub>(aq)</sub> coordination environment. In addition, we report and compare P 2s data from ATP<sub>(aq)</sub> and adenosine mono- and diphosphate (AMP<sub>(aq)</sub> and ADP<sub>(aq)</sub>, respectively) solutions, probing the electronic structure of the phosphate chain and the local environment of individual phosphate units in ATP<sub>(aq)</sub>. Our results provide a comprehensive view of the electronic structure of ATP<sub>(aq)</sub> and Mg<sup>2+</sup>–ATP<sub>(aq)</sub> complexes relevant to phosphorylation and dephosphorylation reactions that are central to bioenergetics in living organisms.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:38802319
%U <Go to ISI:>//WOS:001234460800001
%R 10.1021/jacs.4c03174
%U https://bib-pubdb1.desy.de/record/610905