Amiloride, a specific inhibitor for the Na+-driven flagellar motors of alkalophilic Bacillus.
Amiloride, a specific inhibitor for the Na+-driven flagellar motors of alkalophilic Bacillus.
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阿米洛利，一种嗜碱芽孢杆菌 Na 驱动鞭毛马达的特异性抑制剂。
DOI：
10.1016/s0021-9258(18)68465-0
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Yasuo IrnaeSII
中科院分区：
文献类型：
--
作者：
Shigeru SugiyamaS;E. J. Cragoe;Yasuo IrnaeSII
Na+-driven flagellar motors of alkalophilic Bacillus were found to be inhibited by amiloride, a potent inhibitor for many Na+-coupled systems. A concentration of 0.5 mM of amiloride completely inhibited motility but showed almost no effect on the membrane potential, the intracellular pH homeostasis, and the ATP content of the cells. Furthermore, the activity of a Na+-coupled amino acid transport system was reduced only by half by this concentration of amiloride. Thus, the inhibition of motility of alkalophilic Bacillus by amiloride was rather specific. The inhibition of motility produced by amiloride was restored by increasing Na+ concentrations in the medium. Kinetic analysis of the data revealed that the inhibition was competitive with respect to the concentration of Na+ in the medium. Therefore, it is quite logical to assume that amiloride inhibits the rotation of the Na+-driven flagellar motors of alkalophilic Bacillus by competing with Na+ at the force-generating site of the motor. Some amiloride analogs known to selectively inhibit Na+ channels were potent inhibitors for the flagellar motors, suggesting that the Na+-interacting site of the motors has some similarity to that of the Na+ channels.
