CALORIMETRIC TITRATION OF GALACTOSE BINDING TO GAL REPRESSOR OF E COLI

量热滴定半乳糖与大肠杆菌 gal 阻遏物的结合

• 批准号: 6122030
• 负责人: MICHAEL E RODGERS
• 金额: --
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-05 至 1998-08-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6122030
• 关键词: biological products; biomaterials; biomedical resource; genetics; human tissue; technology /technique development; women's health

The gal operon of E. coli is a classic negative repression system that contains three genes which encode for enzymes required in galactose metabolism. GalR, the gal repressor, regulates transcription from this operon. Its function involves multiple linked equilibria including the basic repressor-inducer binding and repressor-operator interactions. A GalR monomer-dimer equilibrium and interactions with other regulatory proteins (Hu and cAMP-CRP) probably play important roles in in vivo function. The magnitude and linkage of these interactions can be probed in vitro by physical studies. Intrinsic tryptophan fluorescence was used to characterize GalR:D-galactose binding as a function of temperature. The binding appears cooperative, at least at low temperatures, and the estimated van't Hoff enthalpy ( HvH) is -2.5 kcal/mol. Direct calorimetric determination of the thermodynamic parameters for ligand binding to GalR will improve our understanding of the energetics and allosteric control in this system, and of transcriptional regulation in general.

对E. coli是一个典型的负阻遏系统 它含有三个基因，编码 半乳糖代谢 GalR，半乳糖阻遏物，调节 从这个操纵子转录下来 其功能涉及多个链接 平衡，包括基本阻遏物-诱导物结合， 阻遏基因-操纵基因相互作用 GalR单体-二聚体平衡和 与其他调节蛋白（Hu和cAMP-CRP）的相互作用可能 在体内发挥重要作用。 规模和联系 这些相互作用可以通过物理研究在体外探测。 内源性色氨酸荧光用于表征 GalR：D-半乳糖结合作为温度的函数。 的结合 似乎合作，至少在低温下，和估计 范特霍夫焓（HvH）为-2.5 kcal/mol。 直接量热法 测定配体结合的热力学参数 GalR将提高我们对能量学和变构学的理解， 控制中 系统，以及一般的转录调控。