Using Chemical Probes to Assess the Feasibility of Targeting SecA for Developing Antimicrobial Agents against Gram-Negative Bacteria.
Using Chemical Probes to Assess the Feasibility of Targeting SecA for Developing Antimicrobial Agents against Gram-Negative Bacteria.
复制标题
使用化学探针评估以 SecA 为靶点开发针对革兰氏阴性菌的抗菌剂的可行性。
DOI：
10.1002/cmdc.201600421
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发表时间：
2016
期刊：
影响因子：
3.4
通讯作者：
Tai,PhangC
中科院分区：
文献类型：
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作者：
Jin,Jinshan;Hsieh,Ying-Hsin;Cui,Jianmei;Damera,Krishna;Dai,Chaofeng;Chaudhary,ArpanaS;Zhang,Hao;Yang,Hsiuchin;Cao,Nannan;Jiang,Chun;Vaara,Martti;Wang,Binghe;Tai,PhangC
随着耐药性的广泛出现，迫切需要寻找新的抗菌药物，特别是针对革兰氏阴性菌的抗菌药物。沿着这条路线，确定可行的目标是关键的第一步。蛋白质移位酶SecA通常被认为是开发广谱抗菌剂的极好靶点。近年来，我们开发了三种结构类型的SecA抑制剂，已被证明对革兰氏阳性菌非常有效。然而，尽管相同抑制剂在酶测定中对SecA具有强效抑制作用，但我们尚未实现针对革兰氏阴性菌的相同水平的成功。在这项研究中，我们使用代表性的抑制剂作为化学探针，以了解为什么这些抑制剂对革兰氏阴性菌无效。结果验证了我们最初的假设，即对革兰氏阳性菌和革兰氏阴性菌有效性的主要差异在于革兰氏阴性菌外膜构成的额外渗透屏障。我们还发现，负责多药耐药（MDR）的外排泵的表达对这些SecA抑制剂的有效性没有影响。对抑制剂抗性突变体的鉴定和对asecAtsmutant中含有secA的质粒的互补测试表明，单个secA <$azi-9突变增加了抗性，提供了遗传证据，表明SecA确实是细菌中这些抑制剂的靶标。这些结果强烈表明SecA是开发针对革兰氏阴性菌的有效抗菌剂的极好靶标，具有克服MDR的内在能力。未来的一个关键研究方向应该是膜渗透性的优化。
With the widespread emergence of drug resistance, there is an urgent need to search for new antimicrobials, especially those against Gram‐negative bacteria. Along this line, the identification of viable targets is a critical first step. The protein translocase SecA is commonly believed to be an excellent target for the development of broad‐spectrum antimicrobials. In recent years, we developed three structural classes of SecA inhibitors that have proven to be very effective against Gram‐positive bacteria. However, we have not achieved the same level of success against Gram‐negative bacteria, despite the potent inhibition of SecA in enzyme assays by the same inhibitors. In this study, we use representative inhibitors as chemical probes to gain an understanding as to why these inhibitors were not effective against Gram‐negative bacteria. The results validate our initial postulation that the major difference in effectiveness against Gram‐positive and Gram‐negative bacteria is in the additional permeability barrier posed by the outer membrane of Gram‐negative bacteria. We also found that the expression of efflux pumps, which are responsible for multidrug resistance (MDR), have no effect on the effectiveness of these SecA inhibitors. Identification of an inhibitor‐resistant mutant and complementation tests of the plasmids containingsecAin asecAtsmutant showed that a singlesecA‐azi‐9mutation increased the resistance, providing genetic evidence that SecA is indeed the target of these inhibitors in bacteria. Such results strongly suggest SecA as an excellent target for developing effective antimicrobials against Gram‐negative bacteria with the intrinsic ability to overcome MDR. A key future research direction should be the optimization of membrane permeability.