Biosynthesis, structure and function of cell wall in Streptococcus mutans

变形链球菌细胞壁的生物合成、结构和功能

基本信息

批准号：
10379089
负责人：
Natalia Korotkova
金额：
$ 35.97万
依托单位：
UNIVERSITY OF KENTUCKY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-08 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10379089
关键词：
Adherence Affect Anabolism Analytical Chemistry Antibiotics Antimicrobial Resistance Autolysin Autolysis Bacteremia Bacteria Biochemical Biogenesis Biology Carbohydrates Cell Wall Cell division Cell physiology Cell surface Cellular Morphology Charge Chemical Structure Collaborations Defect Dental caries Development Divalent Cations Drug Design Drug Targeting Enzymatic Biochemistry Enzymes Etiology Future Genetic Glucose Glycerol Goals Gram-Positive Bacteria Human In Vitro Infection Infective endocarditis Knowledge Lead Light Link Mass Spectrum Analysis Mechanics Methods Microbial Biofilms Microscopy Modeling Modification Molecular Molecular Genetics Molecular Structure Morphology NMR Spectroscopy Oral cavity Outcome Outcomes Research Pathogenesis Pathway interactions Peptidoglycan Permeability Phenotype Phospholipase A2 Phospholipids Play Polysaccharides Predisposition Preparation Process Property Proteins Publishing Rattus Regulation Reporting Research Resistance Rhamnose Role Septal Region Serotyping Side Signal Transduction Spatial Distribution Streptococcus Streptococcus mutans Streptococcus pyogenes Structure Surface Techniques Testing Transferase Vertebral column Virulence Work antimicrobial antimicrobial drug base carbohydrate biosynthesis carbohydrate structure cell envelope drug development extracellular improved inorganic phosphate insight lipoteichoic acid mutant nanomechanics neutrophil novel novel strategies pathogen quorum sensing recruit targeted treatment therapeutic target therapeutically effective

项目摘要

The cell wall of many species of Lactobacillales consists of multiple peptidoglycan layers decorated with serotype-specific polysaccharides that are characterized by the presence of rhamnose. Streptococcus mutans is a key etiological agent of human dental caries, and has also been implicated in bacteremia and infective endocarditis. Based on the chemical structures of serotype-specific carbohydrates, S. mutans is classified into serotypes c, e, f and k with approximately 70-80% of strains found in the oral cavity classified as serotype c. The serotype c-specific carbohydrate (SCC) of S. mutans is composed of a polyrhamnose backbone with α- linked glucose side-chains. Although carbohydrate structures have been reported for all S. mutans serotypes, our recent insights into the structure of these glycopolymers indicate that the functionally important modification, glycerol phosphate, was overlooked, possibly due to its loss during the purification steps. This new finding justifies a re-examination of the chemical structures of serotype-specific carbohydrates. One of the goals of the proposed study is to determine the molecular structure of SCC isolated from S. mutans using mild, non-destructive methods. Moreover, little is known about the multienzyme processes involved in attachment of the glucose side-chains to the polyrhamnose backbone of SCC and the function of the glycerol phosphate modification in S. mutans. Our preliminary findings revealed that the glycerol phosphate modification plays important roles in S. mutans morphology, autolysis, resistance to antimicrobials and biofilm formation. We propose to identify and functionally characterize the enzymes involved in glucose side-chain attachment to polyrhamnose, and investigate the molecular mechanisms underlying the functions of glycerol phosphate modification in morphology, autolysis and biofilm formation. To accomplish our goals, we will employ streptococcal genetics, in vitro enzymology, NMR spectroscopy of polysaccharides, analytical chemistry, mass spectrometric analysis of phospholipids, and various methods of microscopy including AFM-based nanomechanics. The cell wall biosynthetic machinery is an historically preferred target for the development of novel antimicrobials. In order to validate the pathway of SCC decoration with glycerol phosphate as a potential drug target, we will determine the role of this modification in a rat caries model. Successful outcomes will guide future studies of cell wall biogenesis in other important Gram-positive bacteria and the development of novel strategies to treat S. mutans infections.

许多种类的乳杆菌的细胞壁由多个PepperyDoglycan层组成装饰有血清型特异性多糖，其特征是存在 Rhamnose。链球菌突变是人类龋齿的关键病因学药，并且具有在细菌和感染性心内膜炎中也暗示。基于化学结构血清型特异性碳氢化物，链球菌被分类为血清型C，E，F和K 在归类为血清型C的口腔中发现的菌株中约有70-80％。血清型 S. utans的C特异性碳水化合物（SCC）由polyrhamnose骨架组成，α- 连接的葡萄糖侧链。尽管已经报道了所有的碳水合物结构 S. mutans的血清型，我们最近对这些糖聚合物结构的见解表明，功能上重要的修饰，磷酸甘油，由于其纯化步骤中的损失。这种新发现的理由是对化学物质的重新检查血清型特异性碳氢化物的结构。拟议研究的目标之一是确定使用轻度，无损的SCC从链球菌分离的SCC的分子结构方法。此外，关于附着的多酶过程知之甚少 SCC的Polyrhamnose主链的葡萄糖侧链和甘油的功能链球菌中的磷酸盐修饰。我们的初步发现表明甘油磷酸盐的修饰在S. mutans的形态，自溶，抗性，对抗菌和生物膜形成。我们建议识别并在功能上表征参与葡萄糖侧链附着在Polyrhamnose上的酶，并研究磷酸甘油磷酸盐修饰功能的分子机制在形态，自溶和生物膜形成。为了实现我们的目标，我们将采用链球菌遗传学，体外酶学，多糖的NMR光谱，分析性化学，磷脂的质谱分析以及显微镜的各种方法包括基于AFM的纳米力学。细胞壁生物合成机械在历史上是一种新型抗菌剂的发展目标。为了验证 SCC以磷酸甘油作为潜在药物靶靶标的SCC装饰，我们将确定大鼠中的这种修饰带有模型。成功的结果将指导细胞壁的未来研究其他重要的革兰氏阳性细菌中的生物发生以及新型策略的发展治疗S. mutans感染。