Effects of K+ and Na+ on the proton motive force of respiring Escherichia coli at alkaline pH
Effects of K+ and Na+ on the proton motive force of respiring Escherichia coli at alkaline pH
复制标题
碱性pH条件下K和Na对呼吸大肠杆菌质子动力的影响
DOI：
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发表时间：
1985
影响因子：
3.2
通讯作者：
E. R. Kashket
中科院分区：
文献类型：
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作者：
E. R. Kashket
在碱性介质中培养的大肠杆菌中研究了 K+ 和 Na+ 在维持质子动力 (delta p) 中的作用。在每升含有少于 100 微当量 K+ 和 Na+ 的 Tris 缓冲液（pH 7.8）中呼吸的细胞的正常 delta p 约为 -165 mV。然而，在 pH 8.2 时，δp 显着降低。 pH 8.2 时 delta p 的降低是由于跨膜电位 (delta psi) 显着降低，而内部 pH 值保持在 7.5 至 7.7。当向电池中添加 KCl 或 NaCl（而非 LiCl 或氯化胆碱）时，δ psi 升至外部 pH 值 7.8 时的值。此外，氯化胆碱抑制K+对δpsi的增强。没有一种盐对内部 pH 值有显着影响。该效应可归因于通过已知的 K+ 和 Na+ 转运系统进出细胞的 K+ 或 Na+ 循环的改变。
The role of K+ and Na+ in the maintenance of the proton motive force (delta p) was studied in Escherichia coli incubated in alkaline media. Cells respiring in Tris buffer (pH 7.8) that contained less than 100 microEq of K+ and Na+ per liter had a normal delta p of about -165 mV. At pH 8.2, however, the delta p was reduced significantly. The decrease in delta p at pH 8.2 was due to a marked decrease in the transmembrane potential (delta psi), while the internal pH remained at 7.5 to 7.7. When KCl or NaCl, but not LiCl or choline chloride, was added to the cells, the delta psi rose to the values seen at an external pH of 7.8. In addition, choline chloride inhibited the enhancement of delta psi by K+. None of the salts had a significant effect on the internal pH. The effects can be attributed to alterations of K+ or Na+ cycling in and out of the cells via the known K+ and Na+ transport systems.