Laboratorio de Virología, Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Metepec, Puebla 74630, Mexico.
Posgrado en Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570, Mexico.
Molecules. 2020 Sep 16;25(18):4248. doi: 10.3390/molecules25184248.
Neuraminidase (NA) of influenza viruses enables the virus to access the cell membrane. It degrades the sialic acid contained in extracellular mucin. Later, it is responsible for releasing newly formed virions from the membrane of infected cells. Both processes become key functions within the viral cycle. Therefore, it is a therapeutic target for research of the new antiviral agents. Structure-activity relationships studies have revealed which are the important functional groups for the receptor-ligand interaction. Influenza virus type A NA activity was inhibited by five scaffolds without structural resemblance to sialic acid. Intending small organic compound repositioning along with drug repurposing, this study combined in silico simulations of ligand docking into the known binding site of NA, along with in vitro bioassays. The five proposed scaffolds are -acetylphenylalanylmethionine, propanoic 3-[(2,5-dimethylphenyl) carbamoyl]-2-(piperazin-1-yl) acid, 3-(propylaminosulfonyl)-4-chlorobenzoic acid, ascorbic acid (vitamin C), and 4-(dipropylsulfamoyl) benzoic acid (probenecid). Their half maximal inhibitory concentration (IC) was determined through fluorometry. An acidic reagent 2'--(4-methylumbelliferyl)-α-d-acetylneuraminic acid (MUNANA) was used as substrate for viruses of human influenza H1N1 or avian influenza H5N2. Inhibition was observed in millimolar ranges in a concentration-dependent manner. The IC values of the five proposed scaffolds ranged from 6.4 to 73 mM. The values reflect a significant affinity difference with respect to the reference drug zanamivir ( < 0.001). Two compounds (-acetyl dipeptide and 4-substituted benzoic acid) clearly showed competitive mechanisms, whereas ascorbic acid reflected non-competitive kinetics. The five small organic molecules constitute five different scaffolds with moderate NA affinities. They are proposed as lead compounds for developing new NA inhibitors which are not analogous to sialic acid.
流感病毒的神经氨酸酶（NA）使病毒能够接触细胞膜。它降解细胞外粘蛋白中含有的唾液酸。随后，它负责将新形成的病毒粒子从感染细胞的膜上释放出来。这两个过程都是病毒周期中的关键功能。因此，它是研究新型抗病毒药物的治疗靶点。结构-活性关系研究揭示了哪些是受体-配体相互作用的重要功能基团。流感病毒 A 型 NA 活性被五种与唾液酸无结构相似性的支架抑制。本研究旨在通过重新定位小分子化合物和药物再利用，将配体对接的计算机模拟与体外生物测定相结合，将已知的 NA 结合位点结合在一起。这五个建议的支架是 -乙酰苯丙氨酸甲硫氨酸、丙酸酸 3-[(2,5-二甲基苯基)氨基甲酰基]-2-(哌嗪-1-基)酸、3-(丙氨基磺酰基)-4-氯苯甲酸、抗坏血酸（维生素 C）和 4-（二丙基磺酰胺基）苯甲酸（丙磺舒）。通过荧光法测定它们的半最大抑制浓度（IC）。作为人流感 H1N1 或禽流感 H5N2 病毒的底物，使用酸性试剂 2'--(4-甲基伞形基）-α-d-乙酰神经氨酸（MUNANA）。以浓度依赖的方式观察到抑制作用，在毫摩尔范围内。五个建议的支架的 IC 值范围为 6.4 至 73mM。这些值反映了与参考药物扎那米韦（ < 0.001）相比，它们的亲和力有显著差异。两种化合物（-乙酰二肽和 4-取代苯甲酸）明显表现出竞争性机制，而抗坏血酸则反映出非竞争性动力学。这五个小分子化合物构成了五个具有中等 NA 亲和力的不同支架。它们被提议作为开发与唾液酸不相似的新型 NA 抑制剂的先导化合物。
