XANTHENE-DYE-LABELED PHOSPHATIDYLETHANOLAMINES AS PROBES OF INTERFACIAL PH - STUDIES IN PHOSPHOLIPID-VESICLES
XANTHENE-DYE-LABELED PHOSPHATIDYLETHANOLAMINES AS PROBES OF INTERFACIAL PH - STUDIES IN PHOSPHOLIPID-VESICLES
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DOI：
10.1042/bj2580683
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发表时间：
1989-03-15
影响因子：
4.1
通讯作者：
STEPHENS, T
中科院分区：
文献类型：
--
作者：
KNIGHT, CG;STEPHENS, T
我们一直在开发使用质膜结合的荧光探针来测量活软骨细胞表面的pH值。为此目的，三个亲脂性pH指示剂，通过共价键结合的咕吨染料荧光素，曙红或二氯荧光素磷脂酰乙醇胺的氨基。将探针掺入磷脂囊泡中，并表征pH对荧光的影响。在两个波长激发期间，在单个发射波长下测量荧光，并计算强度的比率。通过将荧光比率拟合到Henderson-Hasselbach方程来确定实验观察到的pKobs值。所有三种探针均充当pH指示剂，曙红基、二氯荧光素基和荧光素基-磷脂酰乙醇胺具有pKobs。值分别为3.5、6.3和7.5。在生理盐浓度下，囊泡膜组成的变化对这些值的影响不大。我们的结论是，这些探针是有前途的候选人在细胞表面的pH值的测量。
We have been developing the use of plasma-membrane-bound fluorescent probes to measure the pH values at the surfaces of living chondrocytes. For this purpose, three lipophilic pH indicators were made by covalently binding the xanthene dyes fluorescein, eosin or dichlorofluorescein to the amino group of phosphatidylethanolamine. The probes were incorporated into phospholipid vesicles and the effect of pH on the fluorescence was characterized. Fluorescence was measured at a single emission wavelength during excitation at two wavelengths, and the ratio of the intensities was calculated. The experimentally observed pKobs values were determined by fitting the fluorescence ratios to the Henderson-Hasselbach equation. All three probes acted as pH indicators, and the eosinyl-, dichlorofluoresceinyl- and fluoresceinyl-phosphatidylethanolamines had pKobs. values of 3.5, 6.3 and 7.5 resepctively. At physiological salt concentrations, changes in the composition of the vesicle membrane had little effect on these values. We concluded that these probes were promising candidates for the measurement of pH values at cell surfaces.