School of Chemistry, Suranaree University of Technology, Nakhon Ratchasima, Thailand.
School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia.
FEBS J. 2020 Nov;287(22):4982-4995. doi: 10.1111/febs.15283. Epub 2020 Mar 23.
Vibrio spp. play a vital role in the recycling of chitin in oceans, but several Vibrio strains are highly infectious to aquatic animals and humans. These bacteria require chitin for growth; thus, potent inhibitors of chitin-degrading enzymes could serve as candidate drugs against Vibrio infections. This study examined NAG-thiazoline (NGT)-mediated inhibition of a recombinantly expressed GH20 β-N-acetylglucosaminidase, namely VhGlcNAcase from Vibrio campbellii (formerly V. harveyi) ATCC BAA-1116. NGT strongly inhibited VhGlcNAcase with an IC of 11.9 ± 1.0 μm and K 62 ± 3 µm, respectively. NGT was also found to completely inhibit the growth of V. campbellii strain 650 with an minimal inhibitory concentration value of 0.5 µm. ITC data analysis showed direct binding of NGT to VhGlcNAcase with a K of 32 ± 1.2 μm. The observed ΔG° of -7.56 kcal·mol is the result of a large negative enthalpy change and a small positive entropic compensation, suggesting that NGT binding is enthalpy-driven. The structural complex shows that NGT fully occupies the substrate-binding pocket of VhGlcNAcase and makes an exclusive hydrogen bond network, as well as hydrophobic interactions with the conserved residues around the -1 subsite. Our results strongly suggest that NGT could serve as an excellent scaffold for further development of antimicrobial agents against Vibrio infections. DATABASE: Structural data are available in PDB database under the accession number 6K35.
Vibrio 属在海洋中甲壳素的循环中起着至关重要的作用，但有几种弧菌菌株对水生动物和人类具有高度传染性。这些细菌的生长需要甲壳素；因此，甲壳素降解酶的有效抑制剂可以作为治疗弧菌感染的候选药物。本研究考察了 NAG-噻唑啉（NGT）对重组表达的 GH20 β-N-乙酰氨基葡萄糖苷酶，即来自 Vibrio campbellii（以前称为 V. harveyi）ATCC BAA-1116 的 VhGlcNAcase 的抑制作用。NGT 强烈抑制 VhGlcNAcase，IC 为 11.9 ± 1.0 μm，K 62 为 ± 3 μm。还发现 NGT 完全抑制 V. campbellii 菌株 650 的生长，最小抑制浓度值为 0.5 μm。ITC 数据分析显示，NGT 与 VhGlcNAcase 直接结合，K 值为 32 ± 1.2 μm。观察到的 ΔG°为-7.56 kcal·mol-1，是由于焓变的大幅度负值和较小的正熵补偿，表明 NGT 结合是焓驱动的。结构复合物表明，NGT 完全占据了 VhGlcNAcase 的底物结合口袋，并形成了一个独特的氢键网络，以及与-1 亚位点周围保守残基的疏水相互作用。我们的结果强烈表明，NGT 可以作为进一步开发抗弧菌感染抗菌剂的优秀支架。DATABASE：结构数据可在 PDB 数据库中以 6K35 的条目号获得。
