Combining X-ray and neutron crystallography with spectroscopy.
Combining X-ray and neutron crystallography with spectroscopy.
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DOI：
10.1107/s2059798316016314
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发表时间：
2017-02-01
期刊：
影响因子：
--
通讯作者：
Moody PC
中科院分区：
文献类型：
--
作者：
Kwon H;Smith O;Raven EL;Moody PC
利用中子晶体学和原位光谱学研究酶的机制进行了讨论。X射线蛋白质晶体学通过确定酶及其复合物的三维结构，对理解生物化学至关重要。然而，由于X射线被电子散射，该技术难以定位H原子的存在和位置（并且无法定位H+离子），这对于理解酶机制通常至关重要。此外，X射线照射，通过光电效应，将扰乱晶体中的氧化还原状态。通过使用单晶分光光度法，可以监测晶体中发生的反应，以捕获中间体或在X射线数据收集期间跟踪光还原。通过使用中子晶体学，可以定位H原子的位置，因为是原子核而不是电子散射中子，并且散射长度不是由原子序数决定的。结合这两种技术可以更深入地了解反应机理和X射线诱导的光还原。
The use of neutron crystallography and in situ spectroscopy to study enzyme mechanism is discussed. X-ray protein crystallography has, through the determination of the three-dimensional structures of enzymes and their complexes, been essential to the understanding of biological chemistry. However, as X-rays are scattered by electrons, the technique has difficulty locating the presence and position of H atoms (and cannot locate H+ ions), knowledge of which is often crucially important for the understanding of enzyme mechanism. Furthermore, X-ray irradiation, through photoelectronic effects, will perturb the redox state in the crystal. By using single-crystal spectrophotometry, reactions taking place in the crystal can be monitored, either to trap intermediates or follow photoreduction during X-ray data collection. By using neutron crystallography, the positions of H atoms can be located, as it is the nuclei rather than the electrons that scatter neutrons, and the scattering length is not determined by the atomic number. Combining the two techniques allows much greater insight into both reaction mechanism and X-ray-induced photoreduction.