ENZYMOLOGY OF BACTERIAL CELL MEMBRANES

细菌细胞膜的酶学

• 批准号: 3124403
• 负责人: JOHN S ANDERSON
• 金额: $ 10.42万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-06-01 至 1990-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3124403
• 关键词: Micrococcaceae; bacteria; cell membrane; cell wall; gel electrophoresis; ion exchange chromatography; lipopolysaccharides; mass spectrometry; membrane activity; membrane permeability; microorganism metabolism; peptidoglycan; radiotracer; teichoate; ultracentrifugation

The objective of this project is to study how the enzymes of the cytoplasmic membrane of Micrococcus luteus, a gram positive bacterium, effect the biosynthesis of teichuronic acid which is covalently linked to the peptidoglycan. A series of intermediates containing undecaprenyl phosphate as carrier lipid effect teichuronic acid biosynthesis by sequential elongation of the carbohydrate chain of teichuronic acid. Modified cell preparations will be used to determine if some of the intermediates can transfer the putative teichuronic acid chain to peptidoglycan. Concomitant peptidoglycan synthesis may also be required. Another objective is to isolate and chemically characterize the unique linkage region oligosaccharide which joins teichuronic acid to peptidoglycan. An enzymatic and chemical degradation scheme based on the presumed structure of the linkage region will be followed by purification. Methylation analysis, mass spectrometry and nuclear magnetic resonance spectroscopy will be used for characterization. The glycosyltransferase which is involved in teichuronic acid chain elongation will be purified so that the mechanism can be determined by which glucosyl residues are incorporated into the polymer with retention of anomeric configuration while the alternate residues of the polymer are incorporated with inversion of configuration. Teichuronidase, an enzyme which degrades teichuronic acid, will be isolated from an organism which can utilize teichuronic acid as growth substrate. Characterization of the enzyme will follow. Immunoelectron microscopy utilizing antibodies directed against teichuronic acid will be used to evaluate the location of teichuronic acid in the cell wall and sites of synthesis in the cytoplasmic membrane. Proteus myxofaciens, a gram negative bacterium, produces an extracellular gel which will be isolated and characterized by methylation analysis, mass spectrometry and nuclear magnetic resonance spectroscopy.

该项目的目的是研究如何酶的 革兰氏阳性菌藤黄微球菌的细胞质膜， 影响共价连接的磷糖醛酸的生物合成 肽聚糖 一系列含十一异戊二烯基的中间体 磷酸盐作为载体脂质影响磷糖醛酸的生物合成 磷糖醛酸的糖链的连续延长。 将使用修饰的细胞制备物来确定是否存在一些 中间体可以将推定的磷醛酸链转移到 肽聚糖。 还可能需要伴随肽聚糖合成。 另一个目的是分离和化学表征独特的 连接区寡糖，其将磷糖醛酸连接到 肽聚糖 酶和化学降解方案的基础上， 连接区的假定结构将随后进行纯化。 甲基化分析、质谱和核磁共振 光谱学将用于表征。 参与磷糖醛酸链的糖基转移酶 延伸将被纯化，以便可以通过以下方式确定该机制： 该葡糖基残基结合到聚合物中， 异头构型，而聚合物的交替残基是 与反转的配置相结合。 将分离出Teichuronidase，一种降解Teichuronic酸的酶 来自可以利用磷糖醛酸作为生长底物的生物体。 随后将对酶进行表征。 利用抗磷酰脲抗体的免疫电子显微术 酸将被用来评估在细胞中的位置teichuronic酸 细胞质膜中的壁和合成位点。 粘液变形杆菌是一种革兰氏阴性细菌， 凝胶，其将被分离并通过甲基化分析表征，质量 光谱法和核磁共振光谱法。