文章基本信息

标题：Reconstitution of the Na+/H+ Antiporter : A New Method for the Determination of H+ Efflux from Na+/H+ Antiporter-Reconstituted Vesicles
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作者：Sayumi SHIBAMOTO ; Satoko YOSHIDA ; Naoto OKU 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：1988
卷号：11
期号：10
页码：669-673
DOI：10.1248/bpb1978.11.669
出版社：The Pharmaceutical Society of Japan
摘要：A Na⁺/H⁺ antiporter was solubilized with octyl-β-D-glucopyranoside from rat renal brush border membrane and reconstituted in egg phosphatidylcholine liposomes. The activity of the antiporter was determined by a new method. Reconstitution was performed in a solution containing a pH-sensitive fluorescence dye, fluorescein isothiocyanatc-dextran (FITC-dextran), at pH 5.5. The reconstituted vesicles, encapsulating FITC-dextran, were incubated at pH 8.0, and the intravesicular pH (pH_i) was determined by monitoring fluorescence change of the dye. An increase in the fluorescence intensity which corresponded to an increase in pH_i was observed. The rate of the increase was dependent on the concentration of the extravesicular Na⁺, and the efflux of H⁺ in the presence of 150 mM sodium gluconate was suppressed by the addition of amiloride. These results show that the Na⁺/H⁺ antiporter was functionally reconstituted and that its activity can be determined simply by the use of FITC-dextran.
关键词：liposome