State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin, People's Republic of China.
College of Pharmacy, Nankai University, Tianjin, People's Republic of China.
Acta Crystallogr F Struct Biol Commun. 2023 Aug 1;79(Pt 8):208-216. doi: 10.1107/S2053230X23005836. Epub 2023 Jul 31.
Sulfolipid-1 (SL-1) is a lipid that is abundantly found in the cell wall of Mycobacterium tuberculosis (Mtb). MtbFadD23 is crucial in the SL-1 synthesis pathway. Previously, 5'-O-[N-(11-phenoxyundecanoyl)sulfamoyl]adenosine (PhU-AMS) has been shown to be a general inhibitor of fatty-acid-adenylating enzymes (FadDs) in Mtb. However, the fatty acyl-AMP ligase (FAAL) class of FadDs, which includes MtbFadD23, appears to be functionally nonredundant in the production of multiple fatty acids. In this study, the ability of PhU-AMS to bind to MtbFadD23 was examined under in vitro conditions. The crystal structure of the MtbFadD23-PhU-AMS complex was determined at a resolution of 2.64 Å. Novel features were identified by structural analysis and comparison. Although PhU-AMS could bind to MtbFadD23, it did not inhibit the FAAL adenylation activity of MtbFadD23. However, PhU-AMS improved the main T value in a differential scanning fluorimetry assay, and a structural comparison of MtbFadD23-PhU-AMS with FadD32 and PA1221 suggested that PhU-AMS blocks the loading of the acyl chain onto Pks2. This study sheds light on the structure-based design of specific inhibitors of MtbFadD23 and general inhibitors of FAALs.
硫脂-1（SL-1）是一种大量存在于结核分枝杆菌（Mtb）细胞壁中的脂质。MtbFadD23 在 SL-1 合成途径中至关重要。先前，5'-O-[N-（11-苯氧基十一烷酰基）磺酰胺基]腺苷（PhU-AMS）已被证明是 Mtb 中脂肪酸腺苷酸化酶（FadDs）的通用抑制剂。然而，包括 MtbFadD23 在内的脂肪酸酰基-AMP 连接酶（FAAL）类 FadDs 在多种脂肪酸的产生中似乎具有功能上的非冗余性。在这项研究中，在体外条件下检查了 PhU-AMS 与 MtbFadD23 结合的能力。MtbFadD23-PhU-AMS 复合物的晶体结构在 2.64 Å 的分辨率下确定。通过结构分析和比较确定了新的特征。尽管 PhU-AMS 可以与 MtbFadD23 结合，但它不能抑制 MtbFadD23 的 FAAL 腺苷酸化活性。然而，PhU-AMS 提高了差示扫描荧光法测定中的主要 T 值，并且 MtbFadD23-PhU-AMS 与 FadD32 和 PA1221 的结构比较表明 PhU-AMS 阻止了酰基链加载到 Pks2 上。这项研究为 MtbFadD23 的基于结构的特异性抑制剂和 FAALs 的通用抑制剂的设计提供了思路。
