Synthesis and Evaluation of Prp-Specific Probes and Prodrugs

项目总结/摘要 需要新的抗生素靶点来对抗耐药细菌。一个新的潜在药物靶点是 噬菌体相关的核糖体蛋白酶（Prp），其被多种厚壁菌门病原体如 金黄色葡萄球菌、肺炎链球菌和艰难梭菌。这些病原体利用Prp 核糖体成熟Prp是一种半胱氨酸蛋白酶，可切割核糖体蛋白的N-末端延伸 L27，在S.金黄色葡萄球菌，Prp是生存所必需的。由于大多数细菌不含这种N- L27上的末端延伸，并且不编码Prp，靶向它应该导致较少的肠道细菌杀伤 对人类健康很重要的东西 使用Prps的不同病原体具有独特的L27可切割序列。在本提案中，我们将研究 不同Prp对L27序列切割的交叉选择性和动力学。我们将确定最小的L27 Prp识别和处理所需的N-末端序列，以及L27 N-末端序列长度 这是跨物种Prp选择性所需的。这些经验教训将应用于合成Prp激活 环丙沙星和依哌唑胺的前药。将测试这些前药对药物的活性和选择性。 含Prp病原体S. aureus、S. pneumoniae和C.艰难梭菌，以及含Prp的药物 细菌鼠李糖乳杆菌这些研究将大大增加我们对选择性的认识， Prps的反应性，并允许靶向杀死使用它们的细菌。

Project Summary/Abstract New antibiotic targets are needed to combat antibiotic-resistant bacteria. A new potential drug target is a phage-related ribosomal protease (Prp), which is used by a variety of Firmicutes pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, and Clostridioides difficile. These pathogens use Prp for ribosomal maturation. Prp is a cysteine protease that cleaves an N-terminal extension of the ribosomal protein L27, and in the case of S. aureus, Prp is essential for survival. Since most bacteria do not contain this N- terminal extension on L27 and do not encode Prp, targeting it should lead to less killing of commensal bacteria that are important for human health. Different pathogens that use Prps have distinctive L27 cleavable sequences. In this proposal, we will study the cross-selectivity and kinetics of L27 sequence cleavage by different Prps. We will identify the minimal L27 N-terminal sequence required for recognition and processing by Prp, and the L27 N-terminal sequence length required for cross-species Prp selectivity. These lessons will be applied to the synthesis of Prp activated prodrugs of ciprofloxacin and eperezolid. These prodrugs will be tested for activity and selectivity against the Prp-containing pathogens S. aureus, S. pneumoniae, and C. difficile, as well as the Prp-containing commensal bacteria Lactobacillus rhamnosus. These studies will greatly increase our knowledge of the selectivity and reactivity of Prps, and allow for the targeted killing of bacteria that use them.