钠和锂离子对大肠杆菌钾离子转运系统的影响。

Effects of sodium and lithium ions on the potassium ion transport systems of Escherichia coli.

作者信息

Sorensen E N, Rosen B P

出版信息

Biochemistry. 1980 Apr 1;19(7):1458-62. doi: 10.1021/bi00548a030.

Abstract

The effects of the cations choline, Li+, and the Na+ on the TrkA and Kdp K+ transport systems in Escherichia coli were studied by observing the accumulation of 204Tl+ and K+. Tl+ uptake via the TrkA system was stimulated by Na+ but not Li+ when compared to choline. A similar effect was observed for K+ transport via the TrkA system. On the other hand, Tl+ uptake via the Kdp system was stimulated more by Li+ than by Na+ when compared to choline. In addition, Li+ enhanced the effectiveness of Rb+ as an inhibitor of Tl+ uptake via the Kdp system. Na+, however, was a more effective stimulator of K+ transport via the Kdp system than Li+. We suggest that Na+ may be involved in the mechanisms of K+ transport via the TrkA and Kdp systems in E. coli.

摘要

通过观察²⁰⁴Tl⁺和K⁺的积累，研究了阳离子胆碱、Li⁺和Na⁺对大肠杆菌中TrkA和Kdp K⁺转运系统的影响。与胆碱相比，通过TrkA系统的Tl⁺摄取受到Na⁺的刺激，但不受Li⁺的刺激。通过TrkA系统的K⁺转运也观察到类似的效果。另一方面，与胆碱相比，通过Kdp系统的Tl⁺摄取受Li⁺的刺激比受Na⁺的刺激更大。此外，Li⁺增强了Rb⁺作为通过Kdp系统摄取Tl⁺的抑制剂的有效性。然而，Na⁺比Li⁺更有效地刺激通过Kdp系统的K⁺转运。我们认为Na⁺可能参与了大肠杆菌中通过TrkA和Kdp系统的K⁺转运机制。