QUANTITATIVE IN VIVO/IN VITRO STUDIES OF CELL PROCESSES

描述：本研究的两个长期目标是：1)获得 生物聚合物过程之间的体内-体外定量关系， 它们出现在只有几个组分的浓缩的多组分溶液中， 2)获得模式生物E. Coli作为一种适应性强的化学和渗透系统。这两个长期目标 是密切相关的。在大肠杆菌中，生物聚合物相互作用发生在高度 拥挤的聚电解质环境，在那里有大量的水和离子 非离子溶质随周围环境的变化而变化(例如 生长介质渗透压的变化)。大分子拥挤， 聚电解质效应，优先相互作用或局部 水、溶质和大分子部位的浓度(所有这些 随着生长条件的变化)必须单独发挥较大的和 对涉及生物聚合物的细胞过程的重要影响；这些 必须了解个体效应，以便在体外和体外进行比较 活体研究。为了实现这些长期目标，Record博士建议如下 体外和/或体内相互关联的一套定量指标 离子-核糖体相互作用、水和核糖体相互作用的研究 细胞质渗透调节物质(和相关的溶质)与蛋白质和 核蛋白，以及大分子拥挤的影响。他提议 用四极离子核磁共振、渗透压法和平衡透析法进行定量 对模型体系的分子和热力学性质的贡献 体外培养。渗透压和渗透保护剂在生长介质中的存在 是决定关键的可重复的、定量的和独立的变量 大肠杆菌细胞质的热力学性质。这两个 水的热力学活度与各种溶质的浓度 (聚合物和非聚合物)在细胞质中可以在 通过改变生长的渗透压和成分可重现的方式 5~6成熟。在生物物理化学水平上的认识 环境影响与细胞过程之间的关系 化学复杂但生物学特性良好的生物体(E.Coli) 具有基本的生物医学意义。

DESCRIPTION: The two long term goals of this research are: 1) To obtain quantitative in vivo-in vitro relationships between biopolymer processes, which occur in the concentrated, multi-solution of only a few components, and 2) To obtain a quantitative characterization of the model organism E. coli as an adaptable chemical and osmotic system. These two long-term goals are closely related. In E. coli, biopolymer interactions occur in a highly crowded, polyelectrolyte environment, where amounts of water and of ionic and nonionic solutes change in response to changes in the surroundings (e.g. changes in osmolarity of the growth medium). Macromolecular crowding, polyelectrolyte effects, and preferential interactions or local concentrations of water, solutes, and macromolecular sites (all of which change with conditions of growth) must individually exert large and important effects on cellular processes involving biopolymers; these individual effects must be understood in order to compare in vitro and in vivo studies. To accomplish these long term goals, Dr. Record proposes as specific aims an interrelated set of quantitative in vitro and/or in vivo studies of ion-ribosome interactions, of interactions of water and cytoplasmic osmolytes (and related solutes) with proteins and nucleoproteins, and of effects of macromolecular crowding. He proposes to use NMR of quadrupolar ions, osmometry and equilibrium dialysis to quantify contributions to molecular and thermodynamic properties of model systems in vitro. The osmolarity and presence of osmoprotectants in the growth medium are reproducible, quantitative and independent variables that determine key thermodynamic properties of the cytoplasm of E. coli. Both the thermodynamic activity of water and the concentrations of various solutes (both polymeric and nonploymeric) in the cytoplasm can be changed in a reproducible manner by changing the osmolarity and composition of the growth medium. An understanding at the biophysical chemical level of the relationship between environmental influences and cellular processes in this chemically complex but biologically well-characterized organism (E. coli) is of fundamental biomedical relevance.