Structure/function studies of biofilm agents from Aa

Aa 生物膜剂的结构/功能研究

基本信息

批准号：
7246661
负责人：
NARAYANAN RAMASUBBU
金额：
$ 22.12万
依托单位：
UNIV OF MED/DENT OF NJ-NJ DENTAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-07-15 至 2009-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7246661
关键词：
Acetylglucosamine Actinobacillus actinomycetemcomitans Active Sites Adherence Adhesions Amino Acids Antibiotic Resistance Antibiotics Antimicrobial Resistance Area Bacteria Binding Sites Cells Class Cleaved cell Complex Crystallization Data Data Set Development Enzymes Excision Exhibits Foundations Glucosamine Goals Gram-Positive Bacteria Growth and Development function Hexosaminidases Host Defense Human Hydrolysis In Vitro Individual Infection Kinetics Length Link Literature Localized Location Maps Medical Device Metabolic Methods Microbial Biofilms Oligosaccharides Organism Pattern Periodontitis Phase Physiological Polymers Process Property Proteins Pseudomonas fluorescens Range Reporting Research Research Personnel Role Site-Directed Mutagenesis Solid Specificity Staphylococcus epidermidis Starvation Structure Structure-Activity Relationship Surface X ray diffraction analysis X-Ray Diffraction Yersinia pestis base beta-n-acetylhexosaminidase cost effective depolymerization design enzyme substrate complex extracellular innovation insight mutant novel novel strategies overpopulation pathogen pathogenic bacteria prevent programs research study

项目摘要

DESCRIPTION: Actinobacillus actinomycetemcomitans and several pathogenic bacteria attach to abiotic surfaces and produce exopolymers that immobilize the bacterial cells on these colonized surfaces. Such colonization of these cells leads to biofilms with metabolic and physiological capabilities distinct from individual cells. Notable unique property of these biofilms is their resistance to antimicrobials. To colonize other virgin surfaces and to overcome starvation associated with overpopulation, cells must detach and disperse from these surfaces. We have previously shown that in Aa, the enzyme dispersin B is capable of assisting in the dispersal process. Additional studies by our group have shown that dispersin B is capable of preventing surface attachment of several related and non-related bacterial species. Since several pathogenic infections are caused by biofilms, new approaches in controlling the biofilm formation that focus on initial attachment of pathogenic bacteria on to the surfaces, in lieu of their antimicrobial resistance, are necessary. In this regard, study of enzymes that prevent the attachment of bacteria to surfaces through the use of extracellular polymeric substances is an underdeveloped area. We show that dispersin B depolymerizes exopolysaccharides that are made up of beta-1,6-linked N-acetylglucosamine (NAG), and is a potential candidate to remove biofilms of many Gram negative and Gram positive bacterial pathogens. Therefore, our long-range goals are to lay the foundation in the development of dispersin B as a broad spectrum anti-biofilm agent. Our immediate focus is on the structure-function studies on this enzyme to elucidate structural determinants that are necessary for its hydrolytic activity. We propose to achieve this through an integrated approach using x-ray crystallographic and mutational analysis. The Specific Aims are: 1. Identify structural determinants governing the mechanism of action of dispersin B. 2. Map the substrate binding site through kinetic analysis using oligomeric substrate of beta-1,6-linked NAG. 3. Define the roles of specific amino acid residues in the enzymatic activity of dispersin B.

描述：伴放线放线杆菌和几种病原菌附着在非生物表面上，并产生外聚合物，将细菌细胞固定在这些定植表面上。这些细胞的这种定殖导致生物膜具有与单个细胞不同的代谢和生理能力。这些生物膜的显着独特特性是它们对抗菌剂的抵抗力。为了在其他原始表面上定殖并克服与人口过剩相关的饥饿，细胞必须从这些表面分离和分散。我们之前已经证明，在 Aa 中，分散酶 B 能够协助分散过程。我们小组的其他研究表明，分散素 B 能够防止几种相关和不相关细菌物种的表面附着。由于几种病原菌感染是由生物膜引起的，因此需要新的控制生物膜形成的方法，重点关注病原菌最初附着在表面上，而不是其抗菌素耐药性。在这方面，通过使用细胞外聚合物来防止细菌附着到表面的酶的研究是一个不发达的领域。我们发现分散素 B 可以解聚由 β-1,6-连接的 N-乙酰氨基葡萄糖 (NAG) 组成的胞外多糖，并且是去除许多革兰氏阴性和革兰氏阳性细菌病原体生物膜的潜在候选者。因此，我们的长期目标是为分散素B作为广谱抗生物膜剂的开发奠定基础。我们当前的重点是对该酶的结构功能研究，以阐明其水解活性所必需的结构决定因素。我们建议通过使用 X 射线晶体学和突变分析的综合方法来实现这一目标。具体目标是： 1. 确定控制分散素 B 作用机制的结构决定因素。 2. 使用 β-1,6-连接的 NAG 寡聚底物通过动力学分析绘制底物结合位点图谱。 3. 定义特定氨基酸残基在分散素 B 酶活性中的作用。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Surface display of Aggregatibacter actinomycetemcomitans autotransporter Aae and dispersin B hybrid act as antibiofilm agents.

放线聚集菌自转运蛋白 Aae 和分散素 B 杂交体的表面展示充当抗生物膜剂。

DOI：
10.1111/omi.12126
发表时间：
2016
期刊：
Molecular oral microbiology
影响因子：
3.7
作者：
Ragunath,C;DiFranco,K;Shanmugam,M;Gopal,P;Vyas,V;Fine,DH;Cugini,C;Ramasubbu,N
通讯作者：
Ramasubbu,N