Liu Ya, Chen Cheng, Sun Le-Yun, Gao Han, Zhen Jian-Bin, Yang Ke-Wu
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education , College of Chemistry and Materials Science , Northwest University , Xi'an 710127 , P. R. China . Email:
RSC Med Chem. 2020 Jan 10;11(2):259-267. doi: 10.1039/c9md00455f. eCollection 2020 Feb 1.
Metallo-β-lactamase (MβL) ImiS contributes to the emergence of carbapenem resistance. A potent scaffold, -substituted benzenesulfonamide, was constructed and assayed against MβLs. The twenty-one obtained molecules specifically inhibited ImiS (IC = 0.11-9.3 μM); was found to be the best inhibitor (IC = 0.11 μM), and and exhibited partially mixed inhibition with of 8.0 and 0.55 μM. The analysis of the structure-activity relationship revealed that the -substitutes improved the inhibitory activity of the inhibitors. Isothermal titration calorimetry (ITC) assays showed that reversibly inhibited ImiS. The benzenesulfonamides exhibited synergistic antibacterial effects against BL21 (DE3) cells with ImiS, resulting in a 2-4-fold reduction in the MIC of imipenem and meropenem. Also, mouse experiments showed that had synergistic efficacy with meropenem and significantly reduced the bacterial load in the spleen and liver after a single intraperitoneal dose. Tracing the ImiS in living cells by at a super-resolution level (3D-SIM) showed that the target was initially associated on the surface of the cells, then there was a high density of uniform localization distributed in the cytosol of cells, and it finally accumulated in the formation of inclusion bodies at the cell poles. Docking studies suggested that the sulfonamide group acted as a zinc-binding group to coordinate with Zn(ii) and the residual amino acid within the CphA active center, tightly anchoring the inhibitor at the active site. This study provides a highly promising scaffold for the development of inhibitors of ImiS, even the B2 subclasses of MβLs.
金属β-内酰胺酶（MβL）ImiS促成了碳青霉烯耐药性的出现。构建了一种有效的支架——对位取代苯磺酰胺，并针对MβLs进行了检测。所获得的21个分子特异性抑制ImiS（IC₅₀ = 0.11 - 9.3 μM）；发现[具体化合物]是最佳抑制剂（IC₅₀ = 0.11 μM），[其他化合物]和[另一化合物]表现出部分混合抑制，IC₅₀分别为8.0和0.55 μM。构效关系分析表明，对位取代基提高了抑制剂的抑制活性。等温滴定量热法（ITC）分析表明，[具体化合物]可逆地抑制ImiS。苯磺酰胺对表达ImiS的BL21（DE3）细胞表现出协同抗菌作用，导致亚胺培南和美罗培南的最低抑菌浓度（MIC）降低2 - 4倍。此外，小鼠实验表明，[具体化合物]与美罗培南具有协同疗效，单次腹腔注射后显著降低了脾脏和肝脏中的细菌载量。通过[荧光标记物]在超分辨率水平（3D-SIM）追踪活细胞中的ImiS表明，该靶点最初与细胞表面相关，然后在细胞胞质溶胶中有高密度的均匀定位分布，最终在细胞两极积累形成包涵体。对接研究表明，磺酰胺基团作为锌结合基团与Zn(ii)以及CphA活性中心内的残留氨基酸配位，将抑制剂紧密锚定在活性位点。这项研究为开发ImiS抑制剂，甚至MβLs的B2亚类抑制剂提供了一个非常有前景的支架。
