High-resolution nuclear magnetic resonance studies of the Lac repressor. 3. Unfolding of the Lac repressor headpiece.
High-resolution nuclear magnetic resonance studies of the Lac repressor. 3. Unfolding of the Lac repressor headpiece.
复制标题
Lac 阻遏物的高分辨率核磁共振研究。
DOI：
10.1021/bi00507a027
复制
发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
Jardetzky,O
中科院分区：
文献类型：
--
作者：
Wemmer,D;Ribeiro,AA;Bray,RP;Wade-Jardetzky,NG;Jardetzky,O
材料和方法 HP 的制备按照先前的描述进行（Ribeiro 等人，1981）。离子强度 (/2)= 1 的标准磷酸盐缓冲液含有 260 mM K2HP04、40 mM KH2PO4、200 mM KCl、4 M 二硫苏糖醇和 4 M 乙二胺基乙酸。离子强度通过稀释从 /2= 1 调整到 /2= 0.01。NMR 实验在斯坦福大学的 360 MHz 光谱仪上进行。磁共振实验室。CD 测量是在斯坦福大学的 Jasco J-40 自动记录分光偏振仪上进行的。测量温度并保持在±1°C。来自斯坦福大学磁共振实验室，斯坦福，加利福尼亚州 94305。接收日期为 1980 年 7 月 21 日。这项研究得到了美国国立卫生研究院 (GM 18098 和 RR 00711) 和国家科学基金会的资助。 (GP23633)，允许对温度变性进行详细分析。在高离子强度 (1 M) 下，解折叠在 85°C 下完成，而在低离子强度 (0.01M) 下，在 65°C 下完成。天然和部分解折叠的结构在解折叠过程中快速交换，并且该过程在所有离子强度下均完全可逆。
Materials and MethodsPreparations of HP were carried out as described previously (Ribeiro et al., 1981). The standard phosphate buffer at ionic strength (/2)= 1 contained 260 mM K2HP04, 40 mM KH2P04, 200 mM KC1,'4 M dithiothreitol, and" 4 M ethylenedinitriloacetic acid. Ionic strength was adjusted by dilution from/2= 1 to/2= 0.01. NMR experiments were performed on the 360-MHz spectrometer at the Stanford Magnetic Resonance Laboratory. CD measurements were made on a Jasco J-40 auto recording spectropolarimeter at Stanford. Temperature was measured and held to±1 C. f From the Stanford Magnetic Resonance Laboratory, Stanford University, Stanford, California 94305. Received July 21, 1980. This research was supported by grants from the National Institutes of Health (GM 18098 and RR 00711) and from the National Science Foundation (GP23633). be followed, allowing a detailed analysis of the temperature denaturation. At high ionic strength (1 M), the unfolding is complete at 85 C, whileat low ionic strength (0.01 M), it is complete by 65 C. Native and partially unfolded structures are in rapid exchange during the unfolding, and the process appears completely reversible at all ionic strengths.