Aoki H, Kawasaki Y, Kodama M
Department of Biochemistry, Faculty of Science, Okayama University of Science, 1-1, Ridai-cho, Okayama, 700-0005 Japan.
J Biol Phys. 2002 Jun;28(2):237-52. doi: 10.1023/A:1019975513772.
A measurement of (2)H spin-lattice relaxation time, T(1), forD(2)O was performed with a high resolution liquid NMR apparatus fortwo samples of dimyristoylphosphatidylethanolamine (DMPE)-D(2)Osystem in a full hydration at varying temperatures of -20, -10, and 5 (°)C, and both components and compositions of differently boundfreezable water molecules were estimated from a best-fitted curve toexperimental inversion recovery data. A choice of the best-fitted curve wasbased on a distribution of weighted residuals for the experimental data. Asingle component was found for a temperature of -20 (°)C. At 5 (°)C, where all the freezable water exists in the liquid state, threecomponents were observed to be characterized by T(1) values ofapproximately 20, 100, and 200 ms, respectively. By comparingcompositions of these individual components with those obtained in ourprevious DSC study, it was revealed that the first and secondarycomponents are members of freezable interlamellar water and the last oneis comparable to bulk water.
使用高分辨率液体核磁共振仪对二肉豆蔻酰磷脂酰乙醇胺（DMPE）-D₂O体系的两个完全水合样品在-20℃、-10℃和5℃的不同温度下进行了重水（D₂O）的（²H）自旋晶格弛豫时间T₁的测量，并根据对实验反转恢复数据的最佳拟合曲线估算了不同结合状态的可冻结水分子的成分和组成。最佳拟合曲线的选择基于实验数据加权残差的分布。在-20℃时发现单一成分。在5℃时，所有可冻结水均以液态存在，观察到三个成分，其T₁值分别约为20、100和200毫秒。通过将这些单个成分的组成与我们之前的差示扫描量热法（DSC）研究中获得的组成进行比较，发现第一和第二成分是可冻结层间水的成分，最后一个成分与体相水相当。
