The Inhibitory Effect of GlmU Acetyltransferase Inhibitor TPSA on Mycobacterium tuberculosis May Be Affected Due to Its Methylation by Methyltransferase Rv0560c
The Inhibitory Effect of GlmU Acetyltransferase Inhibitor TPSA on Mycobacterium tuberculosis May Be Affected Due to Its Methylation by Methyltransferase Rv0560c
复制标题
GlmU乙酰转移酶抑制剂TPSA对结核分枝杆菌的抑制作用可能因其被甲基转移酶Rv0560c甲基化而受到影响
DOI：
10.3389/fcimb.2019.00251
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发表时间：
2019-07-17
影响因子：
5.7
通讯作者：
Ma, Yufang
中科院分区：
文献类型：
--
作者：
Chen, Changming;Han, Xiuyan;Ma, Yufang
结核分枝杆菌双功能酶 GlmU 是抗结核药物的新靶点，参与糖基供体 UDP-N-乙酰氨基葡萄糖的生物合成。在这里，我们发现TPSA（2-[5-(2-{[4-(2-噻吩基)-2-嘧啶基]硫烷基}乙酰基）-2-噻吩基]乙酸）是一种新型的GlmU乙酰转移酶活性抑制剂（IC50：5.3μM）。通过分子对接，通过定点突变确认了GlmU和TPSA的相互作用位点。 TPSA对巨噬细胞中Mtb H37Ra生长和细胞内H37Ra表现出抑制作用（MIC：66.5μM）。为了研究为什么较高浓度（66.5μM）的TPSA能够抑制H37Ra生长，对用TPSA处理的H37Ra的蛋白质组和转录组进行了分析。两种甲基转移酶MRA_0565 (Rv0558)和MRA_0567 (Rv0560c)的表达显着增加。 TPSA与纯化的Rv0558和Rv0560c分别在S-腺苷甲硫氨酸（甲基供体）存在下预孵育，导致其GlmU对乙酰转移酶活性的抑制作用降低。 TPSA 对过表达 Rv0558 和 Rv0560c 的 H37Ra 生长的抑制作用减弱。这些表明甲基转移酶可以修饰 TPSA。随后通过 LC-MS 证实了 Rv0560c 催化的 TPSA 甲基化。因此，TPSA作为GlmU乙酰转移酶活性抑制剂可能为新型抗结核药物提供结构基础。 TPSA 需要通过一些基团进一步修饰，以防止其被甲基转移酶甲基化。
Mycobacterium tuberculosis bifunctional enzyme GlmU is a novel target for anti-TB drugs and is involved in glycosyl donor UDP-N-acetylglucosamine biosynthesis. Here, we found that TPSA (2-[5-(2-{[4-(2-thienyl)-2-pyrimidinyl]sulfanyl}acetyl)-2-thienyl]acetic acid) was a novel inhibitor for GlmU acetyltransferase activity (IC50: 5.3 mu M). The interaction sites of GlmU and TPSA by molecular docking were confirmed by site-directed mutagenesis. TPSA showed an inhibitory effect on Mtb H37Ra growth and intracellular H37Ra in macrophage cells (MIC: 66.5 mu M). To investigate why TPSA at a higher concentration (66.5 mu M) was able to inhibit H37Ra growth, proteome and transcriptome of H37Ra treated with TPSA were analyzed. The expression of two methyltransferases MRA_0565 (Rv0558) and MRA_0567 (Rv0560c) were markedly increased. TPSA was pre-incubated with purified Rv0558 and Rv0560c in the presence of S-adenosylmethionine (methyl donor) respectively, resulting in its decreased inhibitory effect of GlmU on acetyltransferase activity. The inhibition of TPSA on growth of H37Ra with overexpressed Rv0558 and Rv0560c was reduced. These implied that methyltransferases could modify TPSA. The methylation of TPSA catalyzed by Rv0560c was subsequently confirmed by LC-MS. Therefore, TPSA as a GlmU acetyltransferase activity inhibitor may offer a structural basis for new anti-tuberculosis drugs. TPSA needs to be modified further by some groups to prevent its methylation by methyltransferases.