Characterizing the secondary hydration shell on hydrated myoglobin, hemoglobin, and lysozyme powders by its vitrification behavior on cooling and its calorimetric glass-->liquid transition and crystallization behavior on reheating.
Characterizing the secondary hydration shell on hydrated myoglobin, hemoglobin, and lysozyme powders by its vitrification behavior on cooling and its calorimetric glass-->liquid transition and crystallization behavior on reheating.
复制标题
通过冷却时的玻璃化行为和再加热时的量热玻璃-->液体转变和结晶行为来表征水合肌红蛋白、血红蛋白和溶菌酶粉末上的二次水化壳。
DOI：
10.1016/s0006-3495(95)80139-6
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发表时间：
1995
影响因子：
3.4
通讯作者：
E. Mayer
中科院分区：
文献类型：
--
作者：
G. Sartor;A. Hallbrucker;E. Mayer
对于水合高铁肌红蛋白、高铁血红蛋白和溶菌酶粉末，通过以高达约1500 K min-1的速率冷却，约0.3-0.4 g水/g蛋白质至约0.7-0.8 g水/g蛋白质的可冷冻水部分已完全玻璃化，并且冷却速率的影响通过X射线衍射图表征。这种玻璃状但可冻结的水部分在约210 K开始结晶为立方冰，在约240 K开始结晶为六方冰。通过差示扫描量热法的测量已经表明，在以30 K min-1的速率再加热时，该玻璃状但可冻结的水部分经历玻璃->液体转变，起始温度在约164和约174 K之间，宽度在大约9度和大约16度之间，40 J K-1（可冻结水的摩尔数）-1，但玻璃化转变在可冻结水结晶时消失。这些量热特征类似于在合成水凝胶的孔中吸收的水的量热特征，但与玻璃状本体水的量热特征非常不同。与玻璃体水性质的差异归因于大分子片段与可冻结水部分的亲水性相互作用和H-键合，从而使其动态改性。在约0.7- 0.8g水/g蛋白质下观察到完全玻璃化所需的最小或临界冷却速率的突然增加，这归因于水的流动性的突然增加，并且其显著接近Kimmich等人（1990，Biophys. J. 58：1183）。约0.7-0.8 g水/g蛋白质的水合水平大约是完成二次水合壳所需的水平。
For hydrated metmyoglobin, methemoglobin, and lysozyme powders, the freezable water fraction of between approximately 0.3–0.4 g water/g protein up to approximately 0.7–0.8 g water/g protein has been fully vitrified by cooling at rates up to approximately 1500 K min-1 and the influence of cooling rate characterized by x-ray diffractograms. This vitreous but freezable water fraction started to crystallize at approximately 210 K to cubic ice and at approximately 240 K to hexagonal ice. Measurements by differential scanning calorimetry have shown that this vitreous but freezable water fraction undergoes, on reheating at a rate of 30 K min-1, a glass-->liquid transition with an onset temperature of between approximately 164 and approximately 174 K, with a width of between approximately 9 and approximately 16 degrees and an increase in heat capacity of between approximately 20 and approximately 40 J K-1 (mol of freezable water)-1 but that the glass transition disappears upon crystallization of the freezable water. These calorimetric features are similar to those of water imbibed in the pores of a synthetic hydrogel but very different from those of glassy bulk water. The difference to glassy bulk water's properties is attributed to hydrophilic interaction and H-bonding of the macromolecules' segments with the freezable water fraction, which thereby becomes dynamically modified. Abrupt increase in minimal or critical cooling rate necessary for complete vitrification is observed at approximately 0.7–0.8 g water/g protein, which is attributed to an abrupt increase of water's mobility, and it is remarkably close to the threshold value of water's mobility on a hydrated protein reported by Kimmich et al. (1990, Biophys. J. 58:1183). The hydration level of approximately 0.7–0.8 g water/g protein is approximately that necessary for completing the secondary hydration shell.
蛋白质动力学和水合作用。
影响因子：
--
作者：
Frauenfelder,H;Gratton,E
通讯作者：
Gratton,E
激光诱导光解 MbCO 长寿命状态的研究。
影响因子：
2.9
作者：
Srajer,V;Reinisch,L;Champion,PM
通讯作者：
Champion,PM