Protein hydration dynamics in aqueous solution
Protein hydration dynamics in aqueous solution
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DOI：
10.1039/fd9960300227
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发表时间：
1996-01-01
影响因子：
3.4
通讯作者：
Halle, B
中科院分区：
文献类型：
--
作者：
Denisov, VP;Halle, B
用水中氧-17和氢质子自旋弛豫速率作为共振频率的函数，研究了蛋白质在核糖核酸酶A、溶菌酶、肌红蛋白、胰蛋白酶和血清白蛋白水溶液中的水化动力学。弛豫数据符合蛋白质水化动力学的图景，该图是在以前对较小蛋白质的研究基础上提出的，其中负责松弛分散的长寿命水分子与晶体结构中看到的少量完整的水分子相一致。这些完整的水分子，停留时间在10(-9)-10(-3)S范围内，要么被埋在内部空穴中，要么被困在狭窄的缝隙中，要么与金属离子配位。对于蛋白质表面传统水化层中的水分子，弛豫数据表明平均停留时间在10-50ps的范围内，这与高分辨率H-1光谱和计算机模拟一致。弛豫数据还揭示了蛋白质水化的一些更具体的特征，与晶体学显示为空的空腔的水化有关，水被困在大蛋白质的结构域之间，以及埋藏在水团中的亚纳秒180度翻转。
Water oxygen-17 and deuteron spin relaxation rates, measured as a function of resonance frequency, have been used to study the dynamics of protein hydration in aqueous solutions of ribonuclease A, lysozyme, myoglobin, trypsin and serum albumin. The relaxation data conform to the picture of protein hydration dynamics, proposed on the basis of previous studies of smaller proteins, where the long-lived water molecules responsible for the relaxation dispersion are identified with a small number of integral water molecules seen in the crystal structures. These integral water molecules, with residence times in the range 10(-9)-10(-3) s, are either buried in internal cavities, trapped in narrow clefts or coordinated to metal ions. For the water molecules in the traditional hydration layer at the protein surface, the relaxation data suggest an average residence time in the range 10-50 ps, consistent with high-resolution H-1 spectroscopy and computer simulations. The relaxation data also reveal some more specific features of protein hydration, relating to hydration of cavities that appear empty by crystallography, entrapment of water between structural domains of large proteins and subnanosecond 180 degrees flips in buried water clusters.