Southworth-Davies Robert J, Medina Melissa A, Carmichael Ian, Garman Elspeth F
Laboratory of Molecular Biophysics, Department of Biochemistry, Rex Richards Building, South Parks Road, Oxford, OX1 3QU, United Kingdom.
Structure. 2007 Dec;15(12):1531-41. doi: 10.1016/j.str.2007.10.013.
Radiation damage can be a problem when utilizing ionizing X-radiation in macromolecular crystallography. The dose dependence of radiation damage to eight lysozyme crystals at room temperature (292 K) was investigated in order to provide an accurate comparison with cryotemperature (100 K) results and to allow researchers to calculate expected maximum room-temperature-crystal lifetimes prior to data collection. Results of intensity-loss analysis unexpectedly showed that the dose tolerated by a crystal is dependent on the dose rate according to a positive linear relationship (99% correlation coefficient); a 60% increase in dose rate gave a 4-fold increase in crystal lifetime over the range studied. Alternative metrics of damage were also assessed from room temperature data. In the dose-rate range tested (6 Gy s(-1) to 10 Gy s(-1)), data collection at 100 K appears to offer a 26-113 times increase in the lifetime of the crystal.
在大分子晶体学中使用电离X射线时，辐射损伤可能会成为一个问题。为了与低温（100K）结果进行准确比较，并让研究人员在数据收集前计算预期的室温晶体最大寿命，研究了室温（292K）下八种溶菌酶晶体的辐射损伤剂量依赖性。强度损失分析结果意外地表明，晶体耐受的剂量根据正线性关系（相关系数99%）取决于剂量率；在所研究的范围内，剂量率增加60%会使晶体寿命增加4倍。还根据室温数据评估了损伤的替代指标。在测试的剂量率范围（6 Gy s⁻¹至10 Gy s⁻¹）内，在100K下进行数据收集似乎能使晶体寿命延长26至113倍。
