REGULATION OF INTRACELLULAR PH BY HUMAN PERIPHERAL-BLOOD LYMPHOCYTES AS MEASURED BY F-19 NMR
REGULATION OF INTRACELLULAR PH BY HUMAN PERIPHERAL-BLOOD LYMPHOCYTES AS MEASURED BY F-19 NMR
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DOI：
10.1073/pnas.79.24.7944
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
WILSON, DF
中科院分区：
文献类型：
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作者：
DEUTSCH, C;TAYLOR, JS;WILSON, DF
以D，L-2-氨基-3，3-二氟-2-甲基丙酸（F_2MeAla）为探针，用高分辨~（19）F核磁共振波谱法测定人外周血淋巴细胞内pH值。淋巴细胞很容易吸收F2 MeAla的甲酯，内源性酯酶将酯水解为细胞内的游离氨基酸。这个α-甲基氨基酸不被细胞代谢，并且其19 F NMR谱表现出大的pH依赖性位移，因为α-甲基氨基酸是甲基氨基酸。氨基被质子化。19 F位移的大小、19 F NMR的高灵敏度和α-NMR的有利pKa是有利的。F2 MeAla的氨基（pKa = 7.3）允许在25 ℃下测量淋巴细胞的细胞内pH。30.degree. C与. apprx 5-最小采集时间。在各种外部pH值的测量表明，人外周血淋巴细胞调节其内部pH值，这是一个需要消耗代谢能量的过程。在6.8和7.4之间的pH范围内，淋巴细胞保持恒定的内部pH 7.7 ±。0.06 pH单位。在此范围外，细胞内pH值的变化与细胞外pH值。这19 F pH探针的准确性得到证实，通过独立测量细胞内pH值使用5，5-二甲基恶唑烷-2，4-二酮的平衡分布。
The intracellular pH of human peripheral blood lymphocytes was measured by means of high-resolution 19F NMR spectroscopy using D,L-2-amino-3,3-difluoro-2-methylpropanoic acid (F2MeAla) as a probe. Lymphocytes readily took up the methyl ester of F2MeAla, and endogenous esterase hydrolyzed the ester to the free amino acid inside the cell. This .alpha.-methyl amino acid is not metabolized by the cell, and its 19F NMR spectrum exhibits large pH-dependent shifts as the .alpha.-amino group is protonated. The size of the 19F shifts, the high sensitivity of 19F NMR and the favorable pKa of the .alpha.-amino group of F2MeAla (pKa = 7.3) allowed intracellular pH of lymphocytes to be measured at 25.degree.-30.degree. C with .apprx. 5-min acquisition times. Measurements at various external pH values demonstrated that human peripheral blood lymphocytes regulate their internal pH, a process requiring expenditure of metabolic energy. In the pH range between 6.8 and 7.4, lymphocytes maintain a constant internal pH of 7.7 .+-. 0.06 pH unit. Outside this range, intracellular pH changes with extracellular pH. The accuracy of this 19F pH probe was confirmed by independent measurements of intracellular pH using equilibrium distributions of 5,5-dimethyloxazolidine-2,4-dione.