Breaking the Barrier: Mapping protein interactions in the bacterial outer membrane as targets for new antimicrobials

打破障碍：绘制细菌外膜中的蛋白质相互作用作为新抗菌药物的目标

• 批准号: MR/Y012453/1
• 负责人: Neil Ranson
• 金额: $ 279.56万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FY012453%2F1
• 关键词: Breaking; Barrier; Mapping; protein; interactions

Across human history, bacteria have been responsible for a huge burden of disease and mortality that only lessened with the discovery of vaccination and antibiotics. We now face a rising tide of antimicrobial resistance, and are experiencing a slow-moving pandemic of hospital-acquired infections by drug-resistant bacteria. Alongside better prevention, control, and surveillance, there is an urgent need to identify new targets against which we can develop new antibiotic drugs. Of particular concern are the Gram-negative group of bacteria. Of the five microorganisms identified as urgent threats by the US Centres for Disease Control, three are Gram-negative bacteria, and while there are worryingly few new antibiotics in trials, even fewer target Gram-negative bacteria. Membranes, and the proteins associated with them, constitute the majority of current drug targets across multiple disease areas, largely because membranes are the basis for much compartmentalisation and communication in and between cells. Gram-negative bacteria have a unique, additional, protective outer membrane (OM) that shields the bacterium from its environment. The OM is a major barrier to toxins and antibiotics, and is critical for bacterial growth, virulence, pathogenesis, and the formation of biofilms (which are important for establishing many infections). All biological membranes have two leaflets of amphipathic lipid molecules (typically phospholipids) that form a bilayer, and the lipids in each leaflet are different (asymmetric). The bacterial OM is perhaps the most striking example of membrane asymmetry in biology, with an inner leaflet dominated by phospholipids (as in normal membranes), and an outer leaflet dominated by lipopolysaccharide molecules (which are unique to the bacterial membrane). Integral outer membrane proteins (OMPs), which all have a barrel-shaped structure, have thus evolved to fold and function in a different environment to proteins in other membranes: they experience a very rigid membrane because the lipopolysaccharide clumps together. Furthermore, they don't move around very much in the membrane, and their conformations and interactions are dictated by interactions with other proteins and lipopolysaccharide that are missing in other membranes, but essential for bacterial growth and survival. The OM is thus a fascinating environment that could provide a rich source of new targets for antibacterial interventions. In this MRC programme grant, we will integrate functional and structural studies on the bacterial OM, with the latest innovations in protein structure (and protein interaction) prediction, and in our ability to design new proteins that can bind target proteins. Working in the test tube and with whole bacterial cells, we will learn how OMPs naturally fold up and become embedded within the outer membrane, how they interact with each other and with LPS molecules when they're in that membrane, and how these interactions affect the ways proteins work and how bacteria grow. Ultimately, we want to use these discoveries to illuminate new ways of killing bacteria, or at least weakening their defences so that other drugs can kill them. A programme grant is essential because it will allow us to build a talented team that can work together to make discoveries at a pace and scale that would be impossible via individual, smaller project grants, and it will allow us to place the UK at the forefront of this vital area of research.

在整个人类历史上，细菌负责造成疾病和死亡率的巨大负担，这种负担只会通过发现疫苗接种和抗生素来减轻。现在，我们面临着抗菌素抵抗的潮流，并且正在经历耐药细菌的医院获得感染缓慢的大流行。除了更好的预防，控制和监视外，迫切需要确定我们可以开发新的抗生素药物的新靶标。特别关注的是革兰氏阴性细菌。在美国疾病控制中心被确定为紧急威胁的五种微生物中，有三种是革兰氏阴性细菌，尽管试验中的新抗生素令人担忧，但靶标革兰氏阴性细菌的较少。膜及其与之相关的蛋白质构成了多种疾病区域的大多数药物靶标，这主要是因为膜是细胞内和细胞之间大部分区域化和通信的基础。革兰氏阴性细菌具有独特的，额外的保护性外膜（OM），可保护细菌免受其环境的影响。 OM是毒素和抗生素的主要障碍，对于细菌生长，毒力，发病机理和生物膜的形成至关重要（这对于建立许多感染至关重要）。所有生物膜都有两个形成双层的两亲脂质脂质分子（通常是磷脂），每个小叶中的脂质是不同的（不对称）。细菌OM也许是生物学中膜不对称的最引人注目的例子，内部小叶以磷脂为主（如正常膜中），而外部小叶是由脂多糖分子（细菌膜独有的）主导的。整体外膜蛋白（OMP）都具有枪管形结构，因此已进化为在其他膜中的蛋白质中折叠并起作用：它们经历了非常刚性的膜，因为脂多糖糖团在一起。此外，它们在膜上的移动并不多，它们的构象和相互作用是由其他膜中缺少的其他蛋白质和脂多糖的相互作用决定的，但对于细菌生长和生存至关重要。因此，OM是一个引人入胜的环境，可以为抗菌干预措施提供丰富的新目标。在此MRC计划授予中，我们将将有关细菌OM的功能和结构研究与蛋白质结构（和蛋白质相互作用）预测的最新创新进行整合，并在设计可以结合靶蛋白的新蛋白质的能力上。在试管中和整个细菌细胞中工作，我们将学习如何自然折叠并嵌入外膜内，它们在膜中时如何相互相互作用以及与LPS分子相互作用，以及这些相互作用如何影响蛋白质的工作方式以及细菌的生长方式。最终，我们想利用这些发现来阐明杀死细菌的新方法，或者至少削弱了防御能力，以便其他药物可以杀死它们。计划赠款是必不可少的，因为它将允许我们建立一个有才华的团队，可以通过个人，较小的项目赠款来以速度和规模进行发现，这将使我们能够将英国置于这一重要研究领域的最前沿。