Structure and dynamics of bacterial membrane protein - receptor interactions

细菌膜蛋白-受体相互作用的结构和动力学

基本信息

批准号：
8212381
负责人：
Linda M Columbus
金额：
$ 30.41万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-01 至 2014-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8212381
关键词：
Affinity Antibiotics Bacteria Bacterial Outer Membrane Proteins Binding CEACAM1 Caliber Calorimetry Carcinoembryonic Antigen Cell Adhesion Cell Adhesion Molecules Cell Line Cells Chemicals Complementarity Determining Regions Cytoplasm Development Disease Drug Delivery Systems Electron Spin Resonance Spectroscopy Encapsulated Endocytosis Environment Enzyme Inhibitor Drugs Enzyme Inhibitors Escherichia coli Family Fibronectins Foundations Goals Health Height Hela Cells Heparin Human Integrins Life Lipid Bilayers Lipids Liposomes Maps Measures Mediating Membrane Membrane Proteins Meningitis Methods Micelles Molecular Mutagenesis N Domain Neisseria Neisseria gonorrhoeae Nuclear Magnetic Resonance Pathogenesis Pathway interactions Peptides Pharmacologic Substance Protein Binding Proteins Proteoglycan Relaxation Reporting Research Site Solutions Specificity Spectrum Analysis Spin Labels Structure Subgroup System Techniques Testing Therapeutic Thermodynamics Tissues Titrations Variant Vertebral column Work base design expectation extracellular insight interest mutant novel novel therapeutics protein structure protein structure function receptor reconstitution research study vaccine development

项目摘要

DESCRIPTION (provided by applicant): Many obligate bacterial membrane proteins hijack human cellular pathways by mimicking or manipulating host machinery. The goal of this research is to investigate the structure and dynamics of bacterial outer membrane proteins and their interactions with host receptors. Specifically, research is focused on the outer membrane opacity-associated proteins (Opa) from Neisseria gonorrhoeae and Neisseria meningitides, which induce engulfment of the bacterium in non-phagocytic cells by binding to host receptors. Opa proteins bind to various host receptors and are classified into two families based on host receptor selectivity. The larger class, OpaCEA, bind to carcinoembryonic antigen-like cellular adhesion molecules (CEACAMs), and the smaller class, OpaHS, bind to two different receptors; the heparansulfate proteoglycan receptors (HSPGs) directly and indirectly to integrin receptors via a heparin- mediated interaction with fibronectin or vibironectin. Opa proteins are integral outer membrane proteins and predicted to have an eight-stranded 2-barrel fold. Two of the extracellular loops (HV1 and HV2) have the most sequence variation between Opa proteins and determine the host receptors specificity. Not only do the HV loops discriminate between HSPG and CEACAM receptors, but OpaCEA proteins can be further divided into subgroups based on the selective binding to four of the seven CEACAM receptors. Using nuclear magnetic resonance, electron paramagnetic resonance, isothermal titration calorimetry, and mutagenesis, the molecular determinants of these interactions will be determined. The results will provide insight into the pathogenesis of Neisseria gonorrhoeae and Neisseria meningitides and, therefore, the potential for the rational design of novel antibiotics. In addition, the reconstituted Opa proteins may be useful for vaccine development. However, the most novel application of this research lies in the ability of Opa proteins to target host receptors specifically via three different mechanisms to induce endocytosis in non-phagocytic cells. This ability may be useful for liposome pharmaceutical carriers. The potential ability of liposome encapsulated therapeutics (e.g. enzymes, inhibitors, and peptides) to enter the cytoplasm of living cells and possibly tissue selectively is of crucial importance to the treatment of many diseases. Understanding the molecular determinants of the three Opa-mediated entry mechanisms may facilitate the development of liposome delivery mechanisms. PUBLIC HEALTH RELEVANCE: This research aims to determine how bacteria interact with human cells. By gaining an understanding of these molecular interactions, insights into the rational design of novel antibiotics, vaccine development, and targeting of liposome pharmaceutical carriers will be obtained.

描述（由申请人提供）：通过模仿或操纵宿主机械劫持人类细胞蛋白劫持人类细胞途径。这项研究的目的是研究细菌外膜蛋白的结构和动力学及其与宿主受体的相互作用。具体而言，研究集中在淋病奈瑟氏菌和奈瑟氏菌的外膜外透明质相关蛋白（OPA）上，这些蛋白质和奈瑟氏菌属，这些蛋白质通过与宿主受体结合而诱导非孢细胞细胞中的细菌吞没。 OPA蛋白与各种宿主受体结合，并根据宿主受体的选择性分类为两个家族。较大的类，蛋白石，与癌胚抗原样细胞粘附分子（CEACAMS）结合，较小的类，Opahs，与两个不同的受体结合。直接和间接地与整联蛋白受体通过肝素介导的相互作用与纤连蛋白或乙烯蛋白直接与整合蛋白受体直接或间接地与整合蛋白受体。 OPA蛋白是积分的外膜蛋白，预计具有八链的2桶折。两个细胞外回路（HV1和HV2）在OPA蛋白之间具有最大的序列变化，并确定宿主受体的特异性。 HV环不仅可以区分HSPG和CEACAM受体，而且可以根据选择性结合到与七个CEACAM受体中的四种基础上进一步分为亚组。使用核磁共振，电子顺磁共振，等温滴定量热法和诱变，将确定这些相互作用的分子决定因素。结果将提供有关淋病奈瑟氏菌和奈瑟氏菌的发病机理的洞察力，因此是新型抗生素理性设计的潜力。此外，重建的OPA蛋白可能对疫苗开发有用。然而，这项研究的最新应用是OPA蛋白通过三种不同机制专门靶向宿主受体的能力，以诱导非吞噬细胞中的内吞作用。该能力可能对脂质体药物载体有用。脂质体封装的治疗剂（例如酶，抑制剂和肽）进入活细胞的细胞质和可能有选择性组织的潜在能力对于多种疾病的治疗至关重要。了解三种OPA介导的进入机制的分子决定因素可能有助于脂质体递送机制的发展。公共卫生相关性：这项研究旨在确定细菌如何与人类细胞相互作用。通过了解这些分子相互作用，将获得对新型抗生素，疫苗开发和脂质体药物载体靶向的理性设计的见解。