Leroux Juliette, Chesnel Jean-Yves, Ortiz-Mahecha Carlos, Nair Aarathi, Oostenrijk Bart, Pille Laura, Trinter Florian, Schwob Lucas, Bari Sadia
CIMAP, CEA/CNRS/ENSICAEN/Université de Caen Normandie, 14050, Caen, France.
Deutsches Elektronen-Synchrotron DESY, 22603, Hamburg, Germany.
Chemistry. 2025 Feb 17;31(10):e202403665. doi: 10.1002/chem.202403665. Epub 2025 Jan 21.
Gas-phase near-edge X-ray absorption mass spectrometry (NEXAMS) was employed at the carbon and oxygen K-edges to probe the influence of a single water molecule on the protonated phosphotyrosine molecule. The results of the photodissociation experiments revealed that the water molecule forms two bonds, with the phosphate group and another chemical group. By comparing the NEXAMS spectra at the carbon and oxygen K-edges with density functional theory calculations, we attributed the electronic transitions responsible for the observed resonances, especially the transitions due to the presence of the water molecule. We showed that the water molecule leads to a specific spectral feature in the partial ion yield of hydrated fragments at 536.4 eV. Moreover, comparing the NEXAMS spectra with the calculated structures allowed us to identify three possible structures for singly hydrated phosphotyrosine that agree with the observed fragmentation and resonances.
利用气相近边X射线吸收质谱（NEXAMS）在碳和氧的K边来探测单个水分子对质子化磷酸酪氨酸分子的影响。光解离实验结果表明，水分子与磷酸基团和另一个化学基团形成了两个键。通过将碳和氧K边的NEXAMS光谱与密度泛函理论计算结果进行比较，我们确定了导致观察到的共振的电子跃迁，特别是由于水分子的存在而产生的跃迁。我们表明，水分子在536.4 eV处的水合碎片的部分离子产率中导致了特定的光谱特征。此外，将NEXAMS光谱与计算结构进行比较，使我们能够确定单水合磷酸酪氨酸的三种可能结构，这些结构与观察到的碎片化和共振相符。
