Inhibitors of c-di-GMP synthesis and degradation

能够促进多细胞群落中细菌生长的蛋白质和碳水化合物的表达 生物膜是许多人类病原体的重要毒力特性。假单胞 在铜绿假单胞菌和许多其他革兰氏阴性菌中，这些表面结构的形成受到控制， 第二信使环二GMP（c-di-GMP）的细胞水平。c-di-GMP的浓度为 由两类酶的拮抗活性决定。二鸟苷酸环化酶（DGC）催化 形成c-di-GMP，而磷酸二酯酶（PDE）负责降解这种调节性GMP。 二核苷酸。在这个项目中，将使用化学方法来识别和表征DGC的抑制剂 和PDE。铜绿假单胞菌WspR调节几种生物膜组分的产生，包括 富含葡聚糖的PEL多糖，而RocR，一种PDE，已被证明可以调节CupC的产生 菌毛粘附素这两种高活性蛋白质的重组形式被大量纯化， 用于开发c-di-GMP合成和降解的特异性酶促测定。目标1 根据该建议，我们将利用通过有机合成或酶促合成制备的c-di-GMP的合成类似物， 使用WspR的高活性突变体进行合成。它们将不仅作为WspR和RocR的抑制剂进行测试， 还针对铜绿假单胞菌产生的其他DGC和PDE的活性，目的是 鉴定广谱抑制剂。我们还将测试候选抑制剂结合c-di-GMP的能力 受体并干扰天然c-di-GMP配体的结合。活性物质的结构衍生物 将对化合物进行排序和测试，以建立各种化学部分的结构-活性关系。 在目标2中，我们将表征用于在铜绿假单胞菌中体内抑制靶酶的活性化合物 并评估它们对生物膜发展的生物活性。这些化合物也将作为潜在的 由该生物产生的特定外排泵消除的底物。除了提供有价值的 探索c-di-GMP在毒力中作用的研究工具，DGC和PDE抑制剂的鉴定 应该为临床前计划提供基础，该计划旨在开发这些试剂， 靶向生物膜形成的广谱抗菌剂。

Expression of proteins and carbohydrates capable of promoting bacterial growth in multicellular communities called biofilms is an important virulence property of a number of human pathogens. In Pseudomonas aeruginosa and in many other gram-negative bacteria, the formation of these surface structures is controlled by the cellular levels of the second messenger cyclic di GMP (c-di-GMP). The concentrations of c-di-GMP are determined by the antagonistic activities of two classes of enzymes. Diguanylate cyclases (DGCs) catalyze the formation of c-di-GMP while phosphodiesterases (PDEs) are responsible for the degradation of this regulatory dinucleotide. In this project a chemical approach will be used to identify and characterize inhibitors of DGCs and PDEs. The P. aeruginosa WspR regulates the production of several biofilm components including the glucan-rich PEL polysaccharide, while RocR, a PDE, has been shown to regulate the production of the CupC fimbrial adhesin. Recombinant forms of these two highly active proteins were purified in large quantities and were used to develop specific enzymatic assay for c-di-GMP synthesis and degradation. In Aim 1 of this proposal, we will utilize synthetic analogues of c-di-GMP prepared by organic synthesis or by enzymatic synthesis using hyperactive mutants of WspR. They will be tested not only as inhibitors of WspR and RocR but also for their activities against other DGCs and PDEs produced by P. aeruginosa, with the objective of identifying broad-spectrum inhibitors. We will also test the candidate inhibitors for their ability to bind c-di-GMP receptors and interfere with the binding of the natural c-di-GMP ligands. Structural derivatives of active compounds will be ordered and tested to establish structure-activity relationships of various chemical moieties. In Aim 2 we will characterize the active compounds for in vivo inhibition of the target enzymes in P. aeruginosa and assess their biological activities on biofilm development. The compounds will be also tested as potential substrates for elimination by specific efflux pumps produced by this organism. In addition to providing valuable research tools to probe the role of the c-di-GMP in virulence, the identification of DGC and PDE inhibitors should provide the basis for a preclinical program directed towards the development of these reagents into broad-spectrum antimicrobial agents targeting biofilm formation.