Successful flash‐cooling of xenon‐derivatized myoglobin crystals
Successful flash‐cooling of xenon‐derivatized myoglobin crystals
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氙衍生肌红蛋白晶体的成功闪蒸冷却
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
D. Rees
中科院分区：
文献类型：
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作者：
S. Soltis;M. H. Stowell;M. Wiener;G. Phillips;D. Rees
本文首次提出了一种低温冷冻制备氙衍生蛋白质晶体的方法。该方法是基于假设和随后的观察，从一个紧密的结合位点的氙原子的扩散后减压发生在一个时间尺度的分钟。我们已经观察到显着的变化，从肌红蛋白晶体的衍射强度为5分钟后降压从1 MPa的氙。根据这一观察结果，氙衍生的肌红蛋白晶体在20秒内完全减压，在~95 K低温冷却。然后收集晶体学数据集，以2.0 A的分辨率和同晶和异常差异帕特森地图揭示了一个良好有序的氙网站的存在下，占用约0.5。该网站的分期统计质量良好，证明了该方法的实用性。低温冷却氙衍生晶体的能力将使这种重原子取代方法对于大分子的单同晶置换和多同晶置换定相更加有用。
This paper demonstrates for the first time a method for preparing cryocooled xenon-derivatized protein crystals. The method is based upon the hypothesis and subsequent observation that the diffusion of a xenon atom from a tight binding site following depressurization occurs on a timescale of minutes. We have observed significant changes in diffraction intensities from myoglobin crystals for up to 5 min following depressurization from 1 MPa of xenon. In accordance with this observation, a xenon-derivatized myoglobin crystal was cryocooled at ~95 K within 20 s of complete depressurization. A crystallographic data set was then collected to 2.0 A resolution and isomorphous and anomalous difference Patterson maps revealed the presence of a well ordered xenon site with an occupancy of approximately 0.5. Phasing statistics for this site were of good quality and demonstrate the practicality of this method. The ability to cryocool xenon-derivatized crystals will make this heavy-atom substitution method even more useful for single-isomorphous-replacement and multiple-isomorphous-replacement phasing of macromolecules.