Bryant R G, Shirley W M
Biophys J. 1980 Oct;32(1):3-16. doi: 10.1016/S0006-3495(80)84912-5.
Nuclear magnetic resonance (NMR) measurements provide both structural and dynamical information about the molecules in which nuclear resonances are observed. This manuscript addresses NMR relaxation of water protons in protein powder systems. Inclusion of magnetic communication between the water proton spins and protein proton spins leads to a clearer view of water molecule dynamics at the protein surface than has been previously available. We conclude that water molecule motion at the protein surface is somewhat slower than in the solute free solvent, but it is orders of magnitude faster than motions in a rigid ice lattice even in samples hydrated to levels well below what is generally thought to be the full hydration complement of the protein. The NMR relaxation data on lysozyme powders support a model that leaves adsorbed water very fluid at the protein surface with reorientational correlation times for the water shorter than nanoseconds.
核磁共振（NMR）测量提供了有关观测到核共振的分子的结构和动力学信息。本手稿探讨了蛋白质粉末系统中水合质子的NMR弛豫。考虑水合质子自旋与蛋白质质子自旋之间的磁相互作用，能比以往更清晰地了解蛋白质表面水分子的动力学。我们得出结论，蛋白质表面水分子的运动比无溶质溶剂中的运动稍慢，但即使在水合程度远低于通常认为的蛋白质完全水合水平的样品中，其运动速度也比刚性冰晶格中的运动快几个数量级。溶菌酶粉末的NMR弛豫数据支持了一个模型，该模型表明吸附在蛋白质表面的水流动性很强，水的重排相关时间短于纳秒。
