Raj Ritu, Agarwal Nipanshu, Raghavan Sriram, Chakraborti Tapati, Poluri Krishna Mohan, Pande Gaurav, Kumar Dinesh
Centre of Biomedical Research (CBMR), SGPGIMS Campus, Raibareli Road, Lucknow 226014, Uttar Pradesh, India.
Department of Biochemistry & Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India.
ACS Omega. 2021 Feb 1;6(5):3548-3570. doi: 10.1021/acsomega.0c04763. eCollection 2021 Feb 9.
()-a human gastric pathogen-forms a major risk factor for the development of various gastric pathologies such as chronic inflammatory gastritis, peptic ulcer, lymphomas of mucosa-associated lymphoid tissues, and gastric carcinoma. The complete eradication of infection is the primary objective of treating any -associated gastric condition. However, declining eradication efficiencies, off-target effects, and patient noncompliance to prolong and broad-spectrum antibiotic treatments has spurred the clinical interest to search for alternative effective and safer therapeutic options. As natural compounds are safe and privileged with high levels of antibacterial-activity, previous studies have tested and reported a plethora of such compounds with potential in vitro/in vivo anti- activity. However, the mode of action of majority of these natural compounds is unclear. The present study has been envisaged to compile the information of various such natural compounds and to evaluate their binding with histone-like DNA-binding proteins of (referred here as Hup) using in silico molecular docking-based virtual screening experiments. Hup-being a major nucleoid-associated protein expressed by -plays a strategic role in its survival and persistent colonization under hostile stress conditions. The ligand with highest binding energy with Hup-that is, epigallocatechin-(-)gallate (EGCG)-was rationally selected for further computational and experimental testing. The best docking poses of EGCG with Hup were first evaluated for their solution stability using long run molecular dynamics simulations and then using fluorescence and nuclear magnetic resonance titration experiments which demonstrated that the binding of EGCG with Hup is fairly strong (the resultant apparent dissociation constant ( ) values were equal to 2.61 and 3.29 ± 0.42 μM, respectively).
(某病原体)——一种人类胃部病原体——是多种胃部疾病发展的主要风险因素,如慢性炎症性胃炎、消化性溃疡、黏膜相关淋巴组织淋巴瘤和胃癌。彻底根除感染是治疗任何与该病原体相关胃部疾病的首要目标。然而,根除效率下降、脱靶效应以及患者对延长疗程和广谱抗生素治疗的不依从性,激发了临床寻找替代的有效且更安全治疗选择的兴趣。由于天然化合物安全且具有高水平的抗菌活性,先前的研究测试并报道了大量具有潜在体外/体内抗该病原体活性的此类化合物。然而,这些天然化合物中大多数的作用模式尚不清楚。本研究旨在汇编各种此类天然化合物的信息,并使用基于计算机模拟分子对接的虚拟筛选实验评估它们与该病原体的组蛋白样DNA结合蛋白(此处称为Hup)的结合情况。Hup是该病原体表达的一种主要类核相关蛋白,在其在恶劣应激条件下的存活和持续定殖中发挥着关键作用。与Hup具有最高结合能的配体——即表没食子儿茶素 -(-) - 没食子酸酯(EGCG)——被合理选择用于进一步的计算和实验测试。首先使用长时间分子动力学模拟评估EGCG与Hup的最佳对接构象的溶液稳定性,然后使用荧光和核磁共振滴定实验,结果表明EGCG与Hup的结合相当强(所得表观解离常数( )值分别等于2.61和3.29 ± 0.42 μM)。