Eckert Sebastian, Niskanen Johannes, Jay Raphael M, Miedema Piter S, Fondell Mattis, Kennedy Brian, Quevedo Wilson, Iannuzzi Marcella, Föhlisch Alexander
Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany.
Phys Chem Chem Phys. 2017 Dec 6;19(47):32091-32098. doi: 10.1039/c7cp05713j.
The valence orbitals of aqueous histidine under basic, neutral and acidic conditions and their X-ray induced transformations have been monitored through N 1s resonant inelastic X-ray scattering. Using density functional ab initio molecular dynamics simulations in the core-hole state within the Z + 1 approximation, core-excitation-induced molecular transformations are quantified. Spectroscopic evidence for a highly directional X-ray-induced local N-H dissociation within the scattering duration is presented for acidic histidine. Our report demonstrates a protonation-state and chemical-environment dependent propensity for a molecular dissociation, which is induced by the absorption of high energy photons. This case study indicates that structural deformations in biomolecules under exposure to ionizing radiation, yielding possible alteration or loss of function, is highly dependent on the physiological state of the molecule upon irradiation.
通过N 1s共振非弹性X射线散射监测了在碱性、中性和酸性条件下水溶液中组氨酸的价轨道及其X射线诱导的转变。使用Z + 1近似下核心空穴态的密度泛函从头算分子动力学模拟，对核心激发诱导的分子转变进行了量化。给出了酸性组氨酸在散射持续时间内高度定向的X射线诱导局部N-H解离的光谱证据。我们的报告证明了分子解离的质子化状态和化学环境依赖性倾向，这是由高能光子的吸收引起的。本案例研究表明，生物分子在暴露于电离辐射下的结构变形，可能导致功能改变或丧失，高度依赖于辐照时分子的生理状态。
