ATP synthase in slow- and fast-growing mycobacteria is active in ATP synthesis and blocked in ATP hydrolysis direction
ATP synthase in slow- and fast-growing mycobacteria is active in ATP synthesis and blocked in ATP hydrolysis direction
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DOI：
10.1111/j.1574-6968.2010.02123.x
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发表时间：
2010-12-01
影响因子：
2.1
通讯作者：
Bald, Dirk
中科院分区：
文献类型：
--
作者：
Haagsma, Anna C.;Driessen, Nicole N.;Bald, Dirk
ATP合酶是治疗结核病的有效药物靶点，ATP合酶抑制剂是治疗其他生长缓慢的分支杆菌（例如麻风杆菌和溃疡分支杆菌）引起的感染的有希望的候选药物。ATP合酶是结核分枝杆菌能量代谢中的一种必需酶;然而，没有生物化学数据可用于表征ATP合酶在缓慢生长的分枝杆菌菌株中的作用。在这里，我们发现，从缓慢生长的模型菌株牛分枝杆菌BCG倒置膜囊泡是活跃的ATP合成，但ATP合酶显示没有检测到ATP水解活性，并没有建立一个质子动力（PMF）使用ATP作为底物。用甲醇处理以及PMF激活揭示了ATP水解活性，表明内在亚基ATP和抑制性ADP负责抑制水解活性。这些结果表明，该酶是合成ATP所必需的，而不是维持PMF。为了开发作用于ATP合成酶的新型抗分枝杆菌药物，筛选ATP合成抑制剂而不是ATP水解阻断剂可以被视为一种有前途的策略。
ATP synthase is a validated drug target for the treatment of tuberculosis, and ATP synthase inhibitors are promising candidate drugs for the treatment of infections caused by other slow-growing mycobacteria, such as Mycobacterium leprae and Mycobacterium ulcerans. ATP synthase is an essential enzyme in the energy metabolism of Mycobacterium tuberculosis; however, no biochemical data are available to characterize the role of ATP synthase in slow-growing mycobacterial strains. Here, we show that inverted membrane vesicles from the slow-growing model strain Mycobacterium bovis BCG are active in ATP synthesis, but ATP synthase displays no detectable ATP hydrolysis activity and does not set up a proton-motive force (PMF) using ATP as a substrate. Treatment with methanol as well as PMF activation unmasked the ATP hydrolysis activity, indicating that the intrinsic subunit epsilon and inhibitory ADP are responsible for the suppression of hydrolytic activity. These results suggest that the enzyme is needed for the synthesis of ATP, not for the maintenance of the PMF. For the development of new antimycobacterial drugs acting on ATP synthase, screening for ATP synthesis inhibitors, but not for ATP hydrolysis blockers, can be regarded as a promising strategy.