a BIF, Department of Biochemistry , Sri Krishnadevaraya University , Anantapur 515 003 , India.
b Department of Biotechnology , Acharya Nagarjuna University , Guntur 522 510 , India.
J Biomol Struct Dyn. 2017 Aug;35(11):2509-2529. doi: 10.1080/07391102.2016.1223754. Epub 2017 Feb 20.
Pseudomonas aeruginosa is an opportunistic micro-organism causing diseases both in animals and humans. In case of human pathology, the role of P. aeruginosa is one of the major concerns in intensive care septicemia. Presently, the drug resistance strains of P. aeruginosa are arising mainly by developing multiple mechanisms due to its natural and acquired resistance to many of the antimicrobial agents commonly used in clinical practice. As a result, there is a direct need to invent new drugs so that they may restrict the outbreak of multidrug resistant strains. Virtual high-throughput insilico screening, which helps to identify the chemical ligands that bind to the enzymes, is an important tool in drug discovery and the drugs discovered in this way are clinically tested. In this study, Methylisocitratelyase (MICL), which is essential for the survival of the bacterium and which doesn't show any similarity with the humans, was selected to evaluate the functions of high-affinity inhibitors (PPI-analogs) that are identified using the virtual screening approach. By adopting the computational analysis tools, structural, functional, and inhibitor interactions of MICL against P. aeruginosa were identified. The PPIA-32 is found to be the best binding interactions with MICL. PPIA-32 reduces the binding affinity for substrate to residues required for MICL enzyme activity and also Root Mean Square Deviation simulations show the most stable nature of PPA32-MICL(complex) than that of MICL alone, thereby effectively inhibiting the growth of virulent P. aeruginosa. To our surprise, the same phenomenon is also identified with other gram-negative bacteria like Escherichia coli, Klebsiella pneumoniae, and Salmonella typhi.
铜绿假单胞菌是一种机会性病原体，可引起动物和人类的疾病。在人类病理学中，铜绿假单胞菌的作用是重症监护败血症中的主要关注点之一。目前，铜绿假单胞菌的耐药菌株主要是由于其对许多临床上常用的抗菌药物具有天然和获得性耐药性，从而产生多种机制。因此，直接需要发明新的药物，以限制多药耐药菌株的爆发。虚拟高通量计算机筛选有助于识别与酶结合的化学配体，是药物发现的重要工具，并且以这种方式发现的药物在临床上进行了测试。在这项研究中，选择了甲基异柠檬酸裂解酶（MICL），它是细菌生存所必需的，并且与人类没有任何相似之处，以评估使用虚拟筛选方法鉴定的高亲和力抑制剂（PPI-模拟物）的功能。通过采用计算分析工具，鉴定了 MICL 对铜绿假单胞菌的结构，功能和抑制剂相互作用。发现 PPIA-32 与 MICL 具有最佳的结合相互作用。PPIA-32 降低了对 MICL 酶活性所需残基的底物结合亲和力，并且均方根偏差模拟显示 PPA32-MICL（复合物）比单独的 MICL 更稳定，从而有效地抑制了毒力铜绿假单胞菌的生长。令我们惊讶的是，还发现了其他革兰氏阴性菌，例如大肠杆菌，肺炎克雷伯菌和伤寒沙门氏菌也具有相同的现象。
