Molecular mechanism of cephalosporin resistance of N. gonorrhoeae conferred by mutated PBP2

PBP2突变导致淋病奈瑟菌头孢菌素耐药的分子机制

• 批准号: 10467153
• 负责人: Christopher Davies
• 金额: $ 72.83万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-10 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10467153
• 关键词: Active Sites; Acylation; Alleles; Antibiotic Resistance; Antibiotics; Arthritis; Behavior; Binding; Biological Process; Cefixime; Ceftriaxone; Cell Wall; Cephalosporin Resistance; Cephalosporins; Complex; Contracts; Crystallization; Deuterium; Development; Female; Goals; Gonorrhea; Growth; HIV; Hydrogen; Impairment; Individual; Infection; Infertility; Investigation; Lead; Molecular; Molecular Conformation; Monobactams; Morphology; Mosaicism; Movement; Mutate; Mutation; Neisseria gonorrhoeae; Organism; Pelvic Inflammatory Disease; Penicillin Binding Protein 2; Peptides; Peptidoglycan; Peptidyltransferase; Process; Protein Dynamics; Proteins; Public Health; Reaction; Relaxation; Resistance; Resolution; Risk; Role; Serine; Sexually Transmitted Agents; Sexually Transmitted Diseases; Side; Structure; Translating; Variant; X-Ray Crystallography; antimicrobial; beta-Lactams; design; experimental study; fitness; loss of function; molecular dynamics; mutant; preservation; resistance mechanism; resistance mutation; resistant strain; sex

Project Summary Neisseria gonorrhoeae, the causative agent for the sexually transmitted infection gonorrhea, is responsible for over 800,000 infections annually in the U.S. and 78 million cases worldwide. Untreated or untreatable infections can lead to infertility, pelvic inflammatory disease (PID) in females, gonococcal arthritis in both sexes, and an increased risk of both contracting and transmitting HIV. Over the past several decades, the inexorable increase of resistance in this organism toward multiple classes of antibiotics has severely limited treatment options for gonococcal infections. Most alarmingly, resistance against the extended-spectrum cephalosporin (ESC) ceftriaxone poses a serious threat to public health. This situation requires an understanding of antibiotic resistance at the molecular level in order to enable design of new antimicrobials. ESC resistance of N. gonorrhoeae is conferred by mutated forms of penicillin-binding protein 2 (PBP2). In this application, we propose to elucidate the molecular mechanism of resistance, with the overarching hypothesis that mutations in PBP2 restrict the molecular dynamics of the protein. It builds upon our recent understanding of the interactions made by wild-type PBP2 when bound by ESCs and how conformational changes associated with binding and acylation appear restricted in PBP2 derived from ESCR strains. The investigation comprises three aims: Specific Aim 1 is a structure-function analysis of wild-type PBP2 to investigate the importance of specific interactions formed when PBP2 is bound and acylated by cephalosporins. In Specific Aim 2, we will elucidate how key mutations present in PBP2 from ESCR strains of N. gonorrhoeae reduce inactivation by cephalosporins while retaining sufficient biological function to support growth of the organism. Finally, Specific Aim 3 will examine the behavior of PBP2 variants in solution to determine whether mutations hinder protein dynamics. By revealing the molecular mechanisms of how mutations in PBP2 overcome the lethal action of β-lactams, these investigations will enable new strategies for the development of replacement anti-gonococcal agents.

项目摘要 Neisseria Gonorrhoeae是性传播感染淋病的病因，是 在美国，每年有80万多种感染和全球7800万例感染。未经处理或 不可治疗的感染会导致女性，肺炎球菌关节炎的不育症，骨盆炎症性疾病（PID） 在男女中，同时有收缩和传播艾滋病毒的风险增加。在过去的几十年中， 这种生物体对多种类抗生素的耐药性的不可避免的增加受到了严重限制 淋球菌感染的治疗选择。最令人震惊的是，对扩展光谱的抵抗力 头孢菌素（ESC）头孢曲松对公共卫生有严重威胁。这种情况需要一个 了解分子水平的抗生素耐药性，以便设计新的抗菌剂。 淋病猪笼草的ESC耐药性由阴茎结合蛋白2（PBP2）突变形式赋予。 在此应用中，我们建议阐明抗性的分子机制 PBP2突变限制了蛋白质的分子动力学的假设。它建立在我们最近的 了解野生型PBP2在被ESC绑定时进行的相互作用以及如何构象 与来自ESCR菌株的PBP2限制的结合和酰化外观相关的变化。这 投资包括三个目标：特定目标1是对野生型PBP2的结构 - 功能分析 研究当PBP2结合并通过 头孢菌素。在特定的目标2中，我们将阐明如何从ESCR菌株中存在PBP2中的密钥突变 N.淋病菌降低了头孢菌素的灭活，同时保留足够的生物学功能以支持 生物的生长。最后，特定的目标3将研究解决方案中PBP2变体的行为 确定突变是否阻碍蛋白质动力学。通过揭示如何的分子机制 PBP2中的突变克服了β-内酰胺的致命作用，这些投资将使新的策略成为新的策略 替代抗癌症剂的发展。