Structure-Based Design of Sortase Inhibitors for Anti-Infective Therapy

描述（由申请人提供）：耐药细菌的出现是一个日益严重的健康问题。由于耐药性的挑战，新的方法，将不会受到现有的耐药机制，需要抗菌药物的发现。针对细菌毒力进行抗菌化疗是治疗细菌感染的有效途径。分选酶A是一种有吸引力的和经验证的抗毒性靶标，其催化锚定细菌细胞膜上的表面蛋白。表面蛋白有助于细菌粘附、逃避宿主免疫应答、营养获取和宿主细胞入侵。通过抑制分选酶A干扰细菌细胞膜上表面蛋白的展示是抗菌治疗的有效机制方法。目前，没有分选酶抑制剂被批准用于治疗细菌感染。本项目的总体目标是发现和开发用于抗感染治疗的分选酶小分子抑制剂。我们的策略是使用基于结构的药物设计（SBDD），以确定有效的药物样小分子在重组SrtA测定和纤连蛋白结合测定，并将它们定位为开发成药物用于治疗革兰氏阳性细菌感染。这一策略代表了治疗革兰氏阳性细菌感染的创新方法，将提高低剂量现有抗生素的疗效，并减少抗生素耐药性的发展。在初步研究中，我们使用了金黄色葡萄球菌SrtA产生的共晶结构信息，并设计了两类基于乙烯砜弹头模板的分选酶A抑制剂。分子模拟研究表明，这两类乙烯基砜将通过与活性位点半胱氨酸巯基官能团形成可逆的共价键来使分选酶脱附。该提案的主要里程碑将是鉴定具有强效分选酶A抑制作用的选择性先导化合物（IC 50 < 1？M）和低细胞毒性（CC_（50）> 100 1？M）。先导化合物将显示对一组谱酶的选择性，并且在体外研究中将是药代动力学上可接受的。第二阶段将继续开发这些先导化合物，并确定临床开发候选药物（CDC）。 公共卫生相关性：该项目的总体目标是在重组分选酶A测定和纤连蛋白结合测定中鉴定有效的药物样小分子，并将其定位用于将其开发成治疗革兰氏阳性细菌感染的药物。我们的策略是使用基于结构的药物设计（SBDD）来定义这些分选酶A抑制剂。我们将定义分选酶A抑制剂，其是有效的，在一系列分析酶中具有选择性，无细胞毒性并表现出有利的体外药代动力学性质。

DESCRIPTION (provided by applicant): The emergence of drug-resistant bacteria is an increasing health problem. Because of the resistance challenge, novel approaches which will not be subject to existing resistance mechanisms, are required for antimicrobial drug discovery. Targeting bacterial virulence for antimicrobial chemotherapy is an effective approach for bacterial infection. Sortase A is an attractive and validated antivirulent target, which catalyzes anchoring surface proteins on the bacterial cell membrane. Surface proteins contribute to bacterial adhesion, evasion of host immune response, nutrient acquisition and host cell invasion. Interference with the display of surface proteins on the bacterial cell membrane by inhibition of sortase A is an effective mechanistic approach to antibacterial therapy. Currently, no sortase inhibitors have been approved for treatment of bacterial infection. The overall goal of this project is to discover and develop small molecule inhibitors of sortase for anti-infective therapy. Our strategy is to use structure-based drug design (SBDD) to identify potent drug-like small molecules in a recombinant SrtA assay and a fibronectin-binding assay and position them for development into drugs for the treatment of Gram-positive bacterial infections. This strategy represents an innovative approach to the treatment of Gram-positive bacterial infections that will increase the efficacy of existing antibiotics at low doses, and decrease the development of antibiotic resistance. In preliminary studies, we have used the co-crystal structural information generated for Staphylococcus aureus SrtA and designed two classes of sortase A inhibitors based on a vinyl sulfone warhead template. Molecular modeling studies suggest that these two classes of vinyl sulfones will inactivate sortase by forming a reversible, covalent bond with the active site cysteine thiol functionality. The major milestone of this proposal will be the identification of selective lead compounds with potent sortase A inhibition (IC50 < 1 ?M) and low cytotoxicity (CC50 > 100 1 ?M). Lead compounds will display selectivity against a battery of profiling enzymes and will be pharmacokinetically acceptable in in vitro studies. Phase II will continue the development of these lead compounds and lead to the identification of a Clinical Development Candidate (CDC). PUBLIC HEALTH RELEVANCE: The overall goal of this project is to identify potent drug-like small molecules in a recombinant sortase A assay and a fibronectin-binding assay and position them for development them into drugs for the treatment of Gram-positive bacterial infections. Our strategy is to use structure- based drug design (SBDD) to define these inhibitors of sortase A. We will define sortase A inhibitors that are potent, selective in a battery of profiling enzymes, non-cytotoxic and exhibit favorable in vitro pharmacokinetic properties.