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

描述(申请人提供)：抗药性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，抗微生物药物的发现需要不受现有耐药机制制约的新方法。针对细菌毒力进行抗菌化疗是治疗细菌感染的有效方法。山梨酸酶A是一种诱人且有效的抗病毒靶标，它催化将表面蛋白锚定在细菌细胞膜上。表面蛋白对细菌黏附、逃避宿主免疫反应、获取营养物质和宿主细胞入侵具有重要作用。通过抑制分类酶A干扰细菌细胞膜表面蛋白的展示是抗菌治疗的一种有效机制。目前，还没有山梨酸酶抑制剂被批准用于治疗细菌感染。该项目的总体目标是发现和开发用于抗感染治疗的山梨酸酶小分子抑制剂。我们的策略是使用基于结构的药物设计(SBDD)在重组srtA试验和纤维连接蛋白结合试验中鉴定有效的类药物小分子，并将它们定位为治疗革兰氏阳性细菌感染的药物。这一策略代表了一种治疗革兰氏阳性细菌感染的创新方法，它将提高现有低剂量抗生素的疗效，并减少抗生素耐药性的发展。在初步研究中，我们利用金黄色葡萄球菌SrtA产生的共晶结构信息，设计了两类基于乙烯基砜弹头模板的分类酶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部位半胱氨酸硫醇官能团形成可逆的共价键来灭活索尔特酶。这项提案的主要里程碑将是鉴定具有有效的排序酶A抑制作用(IC50和lt；1？m)和低细胞毒性(CC50和gt；100 1？m)的选择性先导化合物。先导化合物将表现出对一系列仿制酶的选择性，并将在体外研究中在药代动力学上可接受。第二阶段将继续开发这些先导化合物，并导致确定临床开发候选者(CDC)。 公共卫生相关性：该项目的总体目标是在重组索拉酶A试验和纤维连接蛋白结合试验中鉴定有效的类药物小分子，并将它们定位为用于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)来定义这些排序酶A的抑制剂。我们将定义有效的、在一系列配置酶中具有选择性的、无细胞毒性的、并表现出良好的体外药代动力学特性的排序酶A抑制剂。

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.