Synchrotron white-beam X-ray topography of ribonuclease S crystals.
Synchrotron white-beam X-ray topography of ribonuclease S crystals.
复制标题
核糖核酸酶 S 晶体的同步加速器白束 X 射线形貌。
DOI：
10.1107/s090744490200121x
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
M. Dudley
中科院分区：
文献类型：
--
作者：
W. Vetter;D. Gallagher;M. Dudley
通过仔细的实验设计，可以记录在环境温度下核糖核酸酶S晶体的索引同步辐射白光X射线形貌图，其定义和对比度与文献中报道的其他蛋白质的单色光束形貌图相当。通过用滤波器从白色光束中排除长于1埃的波长，可以容忍相当于记录约18个形貌图所需的辐射剂量，而不会对样品造成明显的辐射损伤。需要0.5度或更小的布拉格角来选择具有高强度和消光长度仅为样品厚度的几倍的低折射率谐波纯反射。所得的X射线形貌图在某些情况下显示出地形细节，而在另一些情况下显示出甚至没有特征的背景，这被认为是低镶嵌性蛋白质晶体的特征。核糖核酸酶S晶体是有序的单晶，其质量与已通过X射线形貌术研究的其他蛋白质晶体相当。
With careful experimental design, indexed synchrotron white-beam X-ray topographs of ribonuclease S crystals at ambient temperature could be recorded with a definition and contrast comparable to that of monochromatic beam topographs of other proteins reported in the literature. By excluding wavelengths longer than 1 A from the white beam with a filter, a radiation dose equivalent to that required to record about 18 topographs could be tolerated without appreciable radiation damage to the samples. Bragg angles of 0.5 degrees or less were required to select low-index harmonically pure reflections with high intensities and extinction lengths only several times the sample's thickness. The resulting X-ray topographs in some cases showed topographic detail and in others showed the even featureless background that has been considered characteristic of a protein crystal of low mosaicity. The ribonuclease S crystals were well ordered single crystals of a quality comparable to other protein crystals that have been studied by X-ray topography.