Countering antimicrobial resistance: investigating activity of beta-lactamase inhibitors using atomistic simulation and experiment

对抗抗菌素耐药性：使用原子模拟和实验研究 β-内酰胺酶抑制剂的活性

• 批准号: 2625332
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2625332
• 关键词: Countering; antimicrobial; resistance; investigating; activity

Rising antibiotic resistance is a major problem for human health. Resistance to beta-lactams, the single most important antibiotic class, often arises through their breakdown by beta-lactamases (BLs). Many BL producing bacteria are multi-drug resistant and may cause untreatable infections. A clinically important class of BL inhibitors to combat this resistance are diazabicyclooctanes (DBOs), used together with beta-lactams (e.g. avibactam-ceftazidime, relebactam-imipenem) to treat complicated secondary care infections. Interestingly, new DBOs in development (e.g. Nacubactam, Zidebactam) show inhibition of penicillin binding proteins (PBPs, the cellular targets of the -lactams) as well as BLs, leading to a so-called "enhancer" effect upon beta-lactam action and possible use as 'dual mode' antibiotics. To inhibit BLs and PBPs, DBO inhibitors form stable covalent acyl-enzyme complexes. Using multi-scale computer simulations, we have calculated the efficiency of -lactam acyl-enzyme formation and breakdown for a number of BLs, thereby predicting whether individual enzymes can confer resistance to specific beta-lactams (Chem Comm 2014, 50, 14736; J Chem Inf Model 2019, 59, 3365; ACS Catal 2020, 10, 6188) and their susceptibility to BL inhibitors (Biochemistry 2018, 57, 3560). Crystal structures of complexes of key BLs and PBPs with multiple inhibitors are now available and experimental data provide evidence that in some cases these complexes can slowly degrade to regenerate active enzyme, potentially providing a route to inhibitor resistance.This multidisciplinary project aims to address why certain DBOs inhibit both BLs and PBPs, whereas others inhibit BLs only. Computational assays based on multi-scale simulations will be used to assess formation and breakdown of the acyl-enzymes formed by a range of DBOs with clinically relevant serine BLs (e.g. KPC-2, OXA-48 and variants) as well as PBPs from target bacteria. This is challenging, as different reaction mechanisms will need to be explored. The accuracy of these assays will be validated by experimental determination of DBO inhibition of specific BLs and PBPs, using a range of kinetic methods (co-supervisor Spencer). The BL test set will include new variants identified in regions with endemic resistance.The project will provide training in cutting-edge techniques using state-of-the-art facilities in the context of a collaborative multi-disciplinary environment (e.g. www.bristol.ac.uk/amr/). Insights obtained into DBO inhibition will inform development of new DBOs with desirable characteristics, which may contribute to new, effective treatment of bacterial infections.

抗生素耐药性的上升是人类健康的一个主要问题。β -内酰胺类抗生素是最重要的一类抗生素，其耐药性通常是由β -内酰胺酶（BLs）分解引起的。许多产生BL的细菌具有多重耐药性，可能导致无法治疗的感染。临床上对抗这种耐药性的一类重要BL抑制剂是重氮比环辛烷（DBOs），它与β -内酰胺类药物（如阿维巴坦-头孢他啶、再乐巴坦-亚胺培南）一起用于治疗复杂的二级护理感染。有趣的是，正在开发的新型DBOs（如纳库巴坦、齐地巴坦）显示出对青霉素结合蛋白（PBPs，内酰胺的细胞靶点）和BLs的抑制作用，导致对内酰胺作用的所谓“增强剂”作用，并可能用作“双模式”抗生素。为了抑制BLs和PBPs， DBO抑制剂形成稳定的共价酰基酶复合物。利用多尺度计算机模拟，我们计算了许多BL -内酰胺酰基酶形成和分解的效率，从而预测单个酶是否能对特定的β -内酰胺产生耐药性（Chem Comm 2014, 50,14736; J Chem Inf Model 2019, 59,3365; ACS catal2020, 10,6188）及其对BL抑制剂的敏感性（Biochemistry 2018, 57,3560）。目前已经获得了具有多种抑制剂的关键BLs和PBPs复合物的晶体结构，并且实验数据提供证据表明，在某些情况下，这些复合物可以缓慢降解以再生活性酶，这可能为抑制剂抗性提供了一条途径。这个多学科项目旨在解决为什么某些DBOs同时抑制BLs和PBPs，而其他DBOs仅抑制BLs。基于多尺度模拟的计算分析将用于评估一系列具有临床相关丝氨酸BLs（例如KPC-2， OXA-48和变体）的DBOs形成的酰基酶的形成和分解，以及来自目标细菌的PBPs。这是具有挑战性的，因为需要探索不同的反应机制。这些分析的准确性将通过使用一系列动力学方法实验测定DBO对特定BLs和PBPs的抑制来验证（共同主管Spencer）。BL检测集将包括在地方性耐药地区发现的新变异。该项目将在协作的多学科环境（例如www.bristol.ac.uk/amr/）中使用最先进的设施提供尖端技术培训。对DBO抑制的深入研究将为开发具有理想特性的新型DBO提供信息，这可能有助于开发新的、有效的细菌感染治疗方法。