Noguchi C T, Torchia D A, Schechter A N
Proc Natl Acad Sci U S A. 1980 Sep;77(9):5487-91. doi: 10.1073/pnas.77.9.5487.
We have used 13C/1H magnetic double-resonance spectroscopy to measure the amount of sickle hemoglobin polymer within sickle erythrocytes as a function of oxygen saturation. We previously showed that the methods of cross-polarization and scalar decoupling could be used to measure accurately the polymer fraction in deoxygenated sickle hemoglobin solutions [Noguchi, C.T., Torchia, D.A. & Schechter, A.N. (1979) Proc. Natl. Acad. Sci. USA 76, 4936-4940]. Our measurements show that the amount of intracellular deoxyhemoglobin S polymer increases monotonically with decreasing oxygen saturation. Polymer can be detected at oxygen saturation values above 90%. This result can be theoretically explained by the excluded volume effect of the oxyhemoglobin S in the cell. The very high total intracellular hemoglobin concentration (34 g/dl) reduces the amount of soluble deoxyhemoglobin S to about 3 g/dl at 90% oxygen saturation. The agreement between theory and experiment indicates that the equilibrium properties of intracellular polymerization can be described by the analyses resulting from studies of concentrated sickle hemoglobin solutions. The curve for polymer formation as a function of oxygen saturation is roughly hyperbolic whereas that for cell sickling is sigmoidal; the difference is most apparent for measurements at pH 7.65. Intracellular polymer formation may in general have a different relationship to oxygen saturation than cell sickling and may be a more meaningful parameter of the pathophysiological process in sickle cell anemia than cell morphology. In addition, measurements of intracellular polymer should be useful in evaluating potential therapeutic agents.
我们利用¹³C/¹H 磁双共振光谱法来测量镰状红细胞内镰状血红蛋白聚合物的量，该量是氧饱和度的函数。我们先前表明，交叉极化和标量去耦方法可用于准确测量脱氧镰状血红蛋白溶液中的聚合物分数 [野口，C.T.，托尔基亚，D.A. & 谢克特，A.N.（1979年）《美国国家科学院院刊》76，4936 - 4940]。我们的测量结果表明，细胞内脱氧血红蛋白S聚合物的量随氧饱和度降低而单调增加。在氧饱和度值高于90%时可检测到聚合物。这一结果可以从细胞中氧合血红蛋白S的排阻体积效应得到理论解释。细胞内血红蛋白的总浓度非常高（34 g/dl），在90%氧饱和度时，可将可溶性脱氧血红蛋白S的量降低至约3 g/dl。理论与实验的一致性表明，细胞内聚合的平衡特性可以用对浓缩镰状血红蛋白溶液研究所得的分析来描述。聚合物形成量随氧饱和度变化的曲线大致呈双曲线，而细胞镰变的曲线呈S形；在pH 7.65下进行测量时，这种差异最为明显。一般来说，细胞内聚合物形成与氧饱和度的关系可能与细胞镰变不同，并且对于镰状细胞贫血病理生理过程而言，它可能比细胞形态更具意义。此外，细胞内聚合物的测量对于评估潜在治疗药物应该是有用的。
