高效能大分子結晶學相位解析技術之發展現況

Recent Advances in Phasing Techniques for High-Throughput Macromolecular X-Ray Crystallography

江佳旺(Chia-Wang Chiang) ； 李宜靜(Yi-Ching Li) ； 林麗瑩(Li-Ying Lin) ； 謝東儒(Tung-Ju Hsieh) ； 詹迺立(Nei-Li Chan)

《科儀新知》 150期 (2006/02) Pp. 50-58

https://doi.org/10.29662/IT.200602.0006

摘要

X射線結晶學是目前鑑定生物巨分子三維結構最有效、解析度最高且最廣為採用的技術。以此方法進行結構鑑定涉及以下幾個步驟：樣本的純化與結晶、繞射數據的收集、繞射波相位角的鑑定，以及三維結構之建構與修正。除了晶體的取得一直是結構解析過程中主要的瓶頸外，相位角鑑定亦是此技術成功與否的關鍵之一。近年來由於同步輻射光源使用日益普遍，其波長可調的特性搭配具有異常散射能力的晶體，使我們可使用多波長異常散射法快速解決相位問題，本文將介紹此方法的原理及執行方式。

並列摘要

X-ray crystallography is the most effective and widely used tool in determining the high-resolution three-dimensional structure of biomacromolecule. Key steps of this technique include purification and crystallization of target molecule, collection of X-ray diffraction data, phase determination for each reflection, and construction of a structural model followed by rounds of model refinement. Among them, crystallization and phase determination were known to be the main bottlenecks. With the recent instrumentation advances in crystallographic beamlines, the tunability of synchrotron radiation combined with crystals containing anomalous scatterers allow rapid phase determination by the method of multiple-wavelengths anomalous diffraction. This article introduces the theory and experimental procedure of this revolutionary phasing technique.