The University of Texas-RGV, Edinburg, TX, USA.
Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, USA.
SLAS Discov. 2020 Oct;25(9):1072-1086. doi: 10.1177/2472555220934793. Epub 2020 Jun 25.
is a multidrug-resistant (MDR) pathogen and a causative agent of both nosocomial and community-acquired infections. The genes (S and Z) encoding both forms of tyrosyl-tRNA synthetase (TyrRS-S and TyrRS-Z) were cloned and the resulting proteins purified. TyrRS-S and TyrRS-Z were kinetically evaluated and the values for interaction with Tyr, ATP, and tRNA were 172, 204, and 1.5 μM and 29, 496, and 1.9 μM, respectively. The values for interaction with Tyr, ATP, and tRNA were calculated to be 3.8, 1.0, and 0.2 s and 3.1, 3.8, and 1.9 s, respectively. Using scintillation proximity assay (SPA) technology, a druglike 2000-compound library was screened to identify inhibitors of the enzymes. Four compounds (BCD37H06, BCD38C11, BCD49D09, and BCD54B04) were identified with inhibitory activity against TyrRS-S. BCD38C11 also inhibited TyrRS-Z. The IC values for BCD37H06, BCD38C11, BCD49D09, and BCD54B04 against TyrRS-S were 24, 71, 65, and 50 μM, respectively, while the IC value for BCD38C11 against TyrRS-Z was 241 μM. Minimum inhibitory concentrations (MICs) were determined against a panel of clinically important pathogens. All four compounds were observed to inhibit the growth of cultures of both Gram-positive and Gram-negative bacteria organisms with a bacteriostatic mode of action. When tested against human cell cultures, none of the compounds were toxic at concentrations up to 400 μg/mL. In mechanism of inhibition studies, BCD38C11 and BCD49D09 selectively inhibited TyrRS activity by competing with ATP for binding. BCD37H06 and BCD54B04 inhibited TyrRS activity by a mechanism other than substrate competition.
是一种多药耐药（MDR）病原体，也是医院获得性和社区获得性感染的病原体。编码两种形式的酪氨酸-tRNA 合成酶（TyrRS-S 和 TyrRS-Z）的基因（S 和 Z）被克隆，并且纯化了得到的蛋白质。对 TyrRS-S 和 TyrRS-Z 进行了动力学评估，与 Tyr、ATP 和 tRNA 相互作用的 K 值分别为 172、204 和 1.5 μM 和 29、496 和 1.9 μM。与 Tyr、ATP 和 tRNA 相互作用的 K 值分别计算为 3.8、1.0 和 0.2 s 和 3.1、3.8 和 1.9 s。使用闪烁接近测定法（SPA）技术，筛选了一个类似药物的 2000 种化合物文库，以鉴定酶的抑制剂。鉴定出四种化合物（BCD37H06、BCD38C11、BCD49D09 和 BCD54B04）对 TyrRS-S 具有抑制活性。BCD38C11 还抑制 TyrRS-Z。BCD37H06、BCD38C11、BCD49D09 和 BCD54B04 对 TyrRS-S 的 IC 值分别为 24、71、65 和 50 μM，而 BCD38C11 对 TyrRS-Z 的 IC 值为 241 μM。测定了针对一组临床重要病原体的最小抑菌浓度（MIC）。所有四种化合物均观察到以抑菌模式抑制革兰氏阳性和革兰氏阴性细菌的培养物的生长。当在人细胞培养物中进行测试时，在高达 400 μg/mL 的浓度下，没有一种化合物有毒。在抑制机制研究中，BCD38C11 和 BCD49D09 通过与 ATP 竞争结合选择性地抑制 TyrRS 活性。BCD37H06 和 BCD54B04 通过不同于底物竞争的机制抑制 TyrRS 活性。
