Solids NMR Characterization of Bacterial Cell Walls

本项目旨在继续发展固体核磁共振作为表征细菌肽聚糖的工具，特别是枯草芽孢杆菌的肽聚糖。在含有13C和15N标记的氨基酸的特定培养基中生长的细菌的整个细胞和细胞壁将通过固体核磁共振进行鉴定和细胞壁亚结构的定量分析。将开发气相色谱-质谱技术来补充核磁共振数据，并允许在标签混乱的情况下进行完整的分析。细菌细胞壁对这些生物在环境中生存至关重要，其代谢是抗生素攻击的主要焦点。最近的核磁共振实验旨在建立一种新的分析技术，以确定细胞壁交联的细菌。这种细菌很容易运输标记的丙氨酸和赖氨酸，并将它们整合到细胞壁中，而不需要混乱。核磁共振可以用来直接测量细菌细胞壁的交联密度。固体核磁共振作为表征细菌细胞壁中肽聚糖亚结构的工具的重要一步是将该技术扩展到更常研究的细菌，例如b.s urtilis .***//

This project is designed to continue the development of solids state NMR as a tool for characterization of bacterial peptidoglycan, specifically the peptidoglycan of B. subtilis. Both whole cells and cell walls of bacteria grown in defined media containing 13C and 15N -labeled amino acids will be examined by solids state NMR for the identification and quantitative analysis of cell wall substructures. Gas chromatograph-mass spectroscopy techniques will be developed to complement the NMR data and will allow complete analyses in the presence of label scrambling. The bacterial cell wall is vital for the existence of these organisms in the environment and its metabolism represents a major focus for attack by antibiotics. Recent NMR experiments aimed at developing a new analytical technique for determination of cell-wall cross-linking were carried out on the bacterium A. viridans. This bacterium transports both labeled alanine and lysine readily and incorporates them into the cell wall with no scrambling. NMR can then be used to measure directly the cross-link density in the bacterial cell wall. An important step in the development of solids state NMR as a tool for the characterization of peptidoglycan substructures in bacterial cell walls is an extension of the technique to bacteria which are more commonly studied, e.g. B. Subtilis.***//