Thermal contraction of aqueous glycerol and ethylene glycol solutions for optimized protein-crystal cryoprotection
Thermal contraction of aqueous glycerol and ethylene glycol solutions for optimized protein-crystal cryoprotection
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甘油和乙二醇水溶液的热收缩可优化蛋白质晶体冷冻保护
DOI：
10.1107/s2059798316005490
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Thorne, Robert E.
中科院分区：
文献类型：
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作者：
Shen, Chen;Julius, Ethan F.;Tyree, Timothy J.;Moreau, David W.;Atakisi, Hakan;Thorne, Robert E.
冷冻保护剂水溶液在冷却至低温时的热收缩在蛋白质冷冻组织学和生物冷冻保存中具有实际重要性。在前一种情况下，蛋白质分子及其晶格相对于内部和周围溶剂的冷却的差异收缩可能导致晶体损伤和晶体衍射性质的劣化。在这里，在T = 77 K的甘油和乙二醇的水溶液的非晶相密度已被确定。 通过快速冷却体积小至70 pl的液滴，评估其光学透明度并测量其在液氮-氩气溶液中的浮力，测定密度，精度<0.5%至浓度低至30%（w/v）。 在内部溶剂与可用溶剂空间的收缩匹配中使用这些密度由于几个因素而变得复杂，最值得注意的是从蛋白质水合壳中排除冷冻保护剂以及水合水与本体水的收缩行为的预期偏差。目前的方法和结果将有助于发展合理的方法，冷冻保护和理解的溶剂行为的蛋白质晶体。
The thermal contraction of aqueous cryoprotectant solutions on cooling to cryogenic temperatures is of practical importance in protein cryocrystallography and in biological cryopreservation. In the former case, differential contraction on cooling of protein molecules and their lattice relative to that of the internal and surrounding solvent may lead to crystal damage and the degradation of crystal diffraction properties. Here, the amorphous phase densities of aqueous solutions of glycerol and ethylene glycol at T = 77 K have been determined. Densities with accuracies of <0.5% to concentrations as low as 30%(w/v) were determined by rapidly cooling drops with volumes as small as 70 pl, assessing their optical clarity and measuring their buoyancy in liquid nitrogen–argon solutions. The use of these densities in contraction matching of internal solvent to the available solvent spaces is complicated by several factors, most notably the exclusion of cryoprotectants from protein hydration shells and the expected deviation of the contraction behavior of hydration water from bulk water. The present methods and results will assist in developing rational approaches to cryoprotection and an understanding of solvent behavior in protein crystals.