BIOSYNTHESIS OF BACTERIAL CELL WALLS AND MEMBRANES

我们将研究细菌细胞表面的生物合成和组装方面的问题。 结构-细胞壁和细胞膜，与细胞生长和 细胞分裂。粪链球菌ATCC 9790(粪链球菌)将用作 “模范体系”，主要是因为它的形态和模式比较简单 组织。未来的研究将强调：1.自溶者的作用 肽聚糖水解酶(一种N-乙酰壁酰胺酶)与细胞壁生长和 组织。自溶酶将被分离、纯化至均一，并 它的一些性质将被研究。高纯度酶的相互作用 已知的其活性抑制剂，如脂磷壁酸和 将对磷脂进行研究。的合成和排泄动力学 脂磷壁酸抑制剂将在平衡和不平衡期间进行研究 成长。2.条件突变体的分离和性质研究 细胞壁或膜组装、结构、合成或 功能。最初的重点将放在具有缺陷的突变体上 自溶酶系统。3.对观察到的速度变化的详细研究 不同发育阶段细胞的肽聚糖合成和自溶能力 细胞分裂周期。我们将对生物化学特别感兴趣 以及调节正常细胞自溶活性的分子机制 组织。4.自溶酶活性与自溶酶活性关系的研究 青霉素等抑制细胞壁的抗生素的杀菌作用 集合。将调查导致细胞死亡的反应顺序 链霉素(和其他氨基糖苷类抗生素)的作用机制也是如此 青霉素(和其他抑制细胞壁组装的药物)起作用 协同作用。

We will study aspects of the biosynthesis and assembly of bacterial cell surface structures - the cell wall and membrane, in relationship to cellular growth and cell division. Streptococcus faecalis ATCC 9790 (S. faecium) will be used as a "model system", primarily because of its relatively simple shape and mode of division. Future investigations will emphasize: 1. The roles of the autolytic peptidoglycan hydrolase (an N-acetylmuramidase) in cell wall growth and division. The autolytic enzyme will be isolated, purified to homogeniety and a number of its properties will be studied. Interaction of highly purified enzyme with known inhibitors of its activity such as lipoteichoic acids and phospholipids will be studied. The kinetics of synthesis, and excretion of the lipoteichoic acid inhibitor will be studied during both balanced and unbalanced growth. 2. The isolation and study of the properties of conditional mutants with defects in cell wall or membrane assembly, structure, synthesis or function. Initial emphasis will be placed on mutants with defects in their autolytic enzyme system. 3. Detailed studies of observed variations in rates of peptidoglycan synthesis and capacity to autolyze of cells in various stages of the cell division cycle. We will be particularly interested in the biochemical and molecular mechanisms for regulation of autolytic activity during normal cell division. 4. Studies of the relationship of autolytic enzyme activity to the bactericidal action of penicillins and other antibiotics that inhibit cell wall assembly. The sequence of reactions leading to cell death will be investigated as will mechanisms by which streptomycin (and other aminoglycoside antibiotics) and penicillins (and other inhibitors of cell wall assembly) act synergistically.