Probing and manipulating the bacterial cell wall using chemically modified sugars

背景壁磷壁酸(WTA)是革兰氏阳性细菌表面的糖偶联物，在细胞生长、分裂和生物被膜形成等方面发挥着重要作用。WTA的结构因生物而异，但它们都含有甘油-或核糖醇-磷酸聚合物的共同核心。由于WTA在致病过程中是必不可少的，它们的生物合成已被认为是抗菌药物的潜在靶点。我们假设，核糖醇-磷酸的修饰衍生物可以作为选择性和强大的WTA靶向工具，既可以作为成像探针，也可以作为WTA生物合成的靶向抑制剂或调节剂。目的：1.利用化学修饰的核糖醇-磷酸衍生物为WTAS开发一种新的成像平台。合成新型核糖醇-磷酸类似物作为WTA生物合成的选择性调节剂。使用上面开发的工具来获得基本的见解，了解干扰WTA途径中的特定步骤如何影响WTA的组成和分布。新奇的是，该项目解决了目前缺乏针对依赖核糖醇-磷酸的细胞过程的工具。它还提供了一个新的基于细胞的平台来对WTA进行成像和表征特定途径的抑制剂。时间上，抗菌素耐药性是一个主要的、日益普遍的全球健康问题，突显出迫切需要确定新的治疗策略以及稳健的技术来表征其有效性。实验方法这种跨学科的方法结合了强大的化学工具和先进的荧光显微镜技术。标记的核糖醇-磷酸衍生物将被合成，然后喂给相关的革兰氏阳性菌(金黄色葡萄球菌和枯草芽孢杆菌)，纳入WTAS。将得到的标记WTA结构与报告分子结合，可以通过超分辨率和衍射限制荧光显微镜对WTA的时空动力学进行成像。将开发更多的核糖醇-磷酸衍生物作为WTA生物合成途径中特定酶的抑制剂，并将使用新的成像平台进行表征。

BackgroundWall teichoic acids (WTAs) are glycoconjugates on the surface of gram-positive bacteria that play important roles in, for example, cell growth, division and biofilm formation. WTA structures vary among organisms but they all contain common cores of glycerol- or ribitol-phosphate polymers. Since WTAs are essential for pathogenesis, their biosynthesis has been proposed as a potential target for antibacterial agents. We hypothesise that modified derivatives of ribitol-phosphate can be developed as selective and powerful WTA-targeting tools, both as imaging probes and as targeted inhibitors or modulators of WTA biosynthesis.Objectives1. To develop a new imaging platform for WTAs using chemically modified ribitol-phosphate derivatives.2. To synthesise novel ribitol-phosphate analogues as selective modulators of WTA biosynthesis.3. To use the tools developed above to gain fundamental insights into how interfering with specific steps in the WTA pathway impacts on WTA composition and distribution.NoveltyThe project addresses a current lack of tools targeting ribitol-phosphate-depending cellular processes. It also delivers a new cell-based platform to image WTAs and characterise pathway-specific inhibitors.TimelinessAntimicrobial resistance is a major and increasingly prevalent global health concern, underscoring the urgent need for identification of new therapeutic strategies as well as robust technologies to characterise their effectiveness.Experimental approachThe interdisciplinary approach combines powerful chemical tools with advanced fluorescence microscopy techniques. Tagged ribitol-phosphate derivatives will be synthesised and then fed to relevant gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) to be incorporated into WTAs. Conjugation of the resulting tagged WTA structure to a reporter molecule enables imaging of the spatial-temporal dynamics of WTA by super-resolution and diffraction-limited fluorescence microscopy. Additional ribitol-phosphate derivatives will be developed as inhibitors for specific enzymes in the WTA biosynthetic pathway and will be characterised using the new imaging platform.