Zero-dose extrapolation as part of macromolecular synchrotron data reduction
Zero-dose extrapolation as part of macromolecular synchrotron data reduction
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DOI：
10.1107/s0907444903006516
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发表时间：
2003-05-01
影响因子：
2.2
通讯作者：
Ravelli, RBG
中科院分区：
文献类型：
--
作者：
Diederichs, K;McSweeney, S;Ravelli, RBG
在第三代同步加速器站点的大分子晶体的辐射损伤构成了X射线数据收集中的系统误差的主要来源。在这里，一种计算方法，以部分校正观测到的强度在数据减少的描述和调查。该方法包括一个基于冗余的零剂量外推的衰减函数，是适合于一个独特的反射作为剂量的函数的所有观测的强度。它示出在一个测试案例中与弱异常信号，这种概念上简单的校正，当应用到每个独特的反射，可以显着提高平均强度和单波长异常色散相位的准确性，并导致增强实验电子密度图。讨论了该方法的局限性和可能的改进。
Radiation damage to macromolecular crystals at third-generation synchrotron sites constitutes a major source of systematic error in X-ray data collection. Here, a computational method to partially correct the observed intensities during data reduction is described and investigated. The method consists of a redundancy-based zero-dose extrapolation of a decay function that is fitted to the intensities of all observations of a unique reflection as a function of dose. It is shown in a test case with weak anomalous signal that this conceptually simple correction, when applied to each unique reflection, can significantly improve the accuracy of averaged intensities and single-wavelength anomalous dispersion phases and leads to enhanced experimental electron-density maps. Limitations of and possible improvements to the method are discussed.