STRUCTURE OF ORAL BACTERIAL ADHESINS

口腔细菌粘附素的结构

• 批准号: 8075601
• 负责人: TERESA RUIZ
• 金额: $ 34.32万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8075601
• 关键词: Actinobacillus actinomycetemcomitans; Adhesions; Antibiotic-resistant organism; Bacteria; Bacterial Adhesins; Bacterial Adhesion; Binding; Biochemical Genetics; Cell surface; Chemicals; Collagen; Complex; Data; Dental Pellicle; Development; Distal; Ecosystem; Electron Microscopy; Epithelial Cells; Extracellular Matrix; Extracellular Matrix Proteins; Family member; Fimbrial Adhesins; Gram-Negative Bacteria; Homologous Gene; Human; Hybrids; Immunoelectron Microscopy; Individual; Infection; Invaded; Maps; Mediating; Microbial Biofilms; Nature; Oral; Oral cavity; Periodontal Diseases; Porphyromonas gingivalis; Process; Proteins; Resolution; Roentgen Rays; Salivary; Staging; Streptococcus gordonii; Streptococcus parasanguis; Streptococcus sanguis; Structure; Surface; System; Systemic disease; Techniques; Technology; Tissues; Treponema denticola; Tubulin; Work; appendage; electron tomography; fimbria; image processing; infancy; insight; molecular mass; mutant; novel; novel therapeutics; oral bacteria; oral streptococci; receptor; receptor binding; surface coating; three dimensional structure

DESCRIPTION (provided by applicant): The oral cavity is inhabited by more than 500 species of Gram-positive and Gram-negative bacteria, which exist in a complex ecosystem referred to as a biofilm. Biofilm formation is initiated by the attachment of oral streptococci to the acquired salivary pellicle coating the surfaces of the oral cavity. As the biofilm develops and matures, conditions become propitious for the attachment of the late bacterial colonizers, which are associated with periodontal disease to the existing biofilm. Bacterial adhesion to the acquired salivary pellicle or to host receptors is a crucial step for biofilm formation, bacterial colonization and infection. Bacterial adhesion is mediated by fimbrial and non-fimbrial adhesins, which are proteinaceous appendages displayed on the surface of bacteria containing the receptor binding domains. Fimbrial adhesins form long filamentous structures composed of multiple copies of either a single subunit or multiple subunits. The long-fimbriae of S. parasanguis are composed of multiple subunits of Fap1 (fimbriae-associated protein 1), which are crucial for biofilm formation. Fap-1 homologues have recently been found in other streptococcal family members. Non-fimbrial adhesins form shorter structures comprised of either a single subunit or a small number of identical subunits specifically folding to expose the receptor binding domain at the distal-end. A. actinomycetemcomitans uses specific non-fimbrial adhesins to adhere to and invade into epithelial cells as well as interacting with extracellular matrix proteins. EmaA (Extracellular matrix protein adhesin-A) is a newly discovered non-fimbrial adhesin of A. actinomycetemcomitans involved in binding to collagen and tubulin in the host tissue. EmaA is a multimeric autotransporter protein, which forms structures on the bacterial cell surface by oligomerization of either 3 or 4 subunits (total molecular mass of 600-800 kDa). Structural information on this adhesin and/or the adhesin/receptor complexes is unknown. Detailed 3D structural information on adhesin/receptor interactions is extremely important for the development of next generation therapeutics due to the increase number of antibiotic resistant organisms. To date, however, there is a paucity of structural information regarding oral bacteria. In this application, we propose to determine the 3D structure of the adhesins and adhesin/receptor complexes of both an early bacterial colonizer (Fap-1) and a late colonizer (EmaA) essential to gain insights into the different stages of the pathogenic process. We will carry out these studies using novel techniques of electron microscopy and image processing. Our work will provide the first 3D structural data for these adhesins and the respective adhesin/receptor complexes. PROJECT NARRATIVE: The human oral cavity is inhabited by more than 500 species of bacteria, which are responsible for causing oral and serious extra-oral systemic diseases. Bacterial adhesion, mediated by adhesins on the cell surface, is a crucial step for biofilm formation, colonization, and infection. We will determine the 3D structure of the adhesins and adhesin/receptor complexes, which is essential to gain insights into the different stages of the pathogenic process.

描述（由申请人提供）：口腔被500多种革兰氏阳性和革兰氏阴性细菌居住，这些细菌存在于复杂的生态系统中，称为生物膜。生物膜的形成是通过将口腔链球菌附着在获得的唾液细胞涂层上的。随着生物膜的发展和成熟，条件对已晚细菌殖民剂的附着有利，这与牙周疾病与现有生物膜有关。对获得的唾液颗粒或宿主受体的细菌粘附是生物膜形成，细菌定植和感染的关键步骤。细菌粘附是由纤维化和非膜状粘附蛋白介导的，这些粘附蛋白是蛋白质附属物，显示在含有受体结合域的细菌表面上。纤维化粘附素形成长丝状结构，由单个亚基或多个亚基的多个副本组成。 S. parasanguis的长膜膜由FAP1的多个亚基（Fimbriae相关蛋白1）组成，这对于生物膜形成至关重要。最近在其他链球菌家族成员中发现了FAP-1同源物。非膜粘附素形成较短的结构，由单个亚基或少数相同的亚基组成，专门折叠以暴露远端末端的受体结合结构域。 A.放线症菌Comcitans使用特定的非膜粘附素来粘附并侵入上皮细胞，并与细胞外基质蛋白相互作用。 EMAA（细胞外基质蛋白粘附素-A）是一种新发现的非膜状粘附蛋白，伴有与宿主组织中与胶原蛋白和微管蛋白结合的放线菌ceTemcitans。 EMAA是一种多聚体自转运蛋白，它通过3或4个亚基的寡聚（总分子量为600-800 kDa）在细菌细胞表面形成结构。有关该粘附素和/或粘附素/受体复合物的结构信息尚不清楚。详细的3D结构信息有关粘附蛋白/受体相互作用，由于抗生素耐药生物的数量增加，对于下一代治疗剂的发展至关重要。然而，迄今为止，关于口腔细菌的结构信息很少。在此应用中，我们建议确定早期细菌菌落剂（FAP-1）和晚期结肠剂（EMAA）的粘附素和粘附素/受体复合物的3D结构，即可洞悉致病过程的不同阶段。我们将使用电子显微镜和图像处理的新技术进行这些研究。我们的工作将为这些粘附素和相应的粘附素/受体复合物提供第一个3D结构数据。 项目叙述：人类口腔被500多种细菌居住，这些细菌造成口腔和严重的口腔外系统疾病。细菌粘附，由细胞表面粘附介导，是生物膜形成，定殖和感染的关键步骤。我们将确定粘附素和粘附素/受体复合物的3D结构，这对于获得致病过程的不同阶段至关重要。