Intracellular Trp repressor levels in Escherichia coli
Intracellular Trp repressor levels in Escherichia coli
复制标题
大肠杆菌细胞内色氨酸阻遏蛋白水平
作者：
R. Gunsalus;A. G. Miguel;G. Gunsalus
使用针对纯化的色氨酸阻遏蛋白的抗血清开发了大肠杆菌色氨酸阻遏蛋白的放射免疫测定法。该测定用于直接测量几种大肠杆菌 K-12 和 B/r 菌株的细胞内 Trp 阻遏蛋白含量。阻遏蛋白水平随生长培养基中 L-色氨酸浓度变化 2.5 至 3 倍（每毫克蛋白质含有 15 至 44 ng 阻遏蛋白）。细胞生长速率和培养年龄均对细胞内阻遏物浓度没有显着影响。向生长培养基中添加 L-色氨酸导致细胞内色氨酸阻遏物水平降低。在培养基中存在和不存在 L-色氨酸的情况下，每个细胞的天然色氨酸阻遏分子的绝对量分别在 120 和 375 个二聚体之间变化。假设细胞内体积为 7.3 微升/10(10) 大肠杆菌细胞，Trp 阻遏物浓度根据细胞外色氨酸水平在 270 至 850 nM 之间变化。这些发现代表了对大肠杆菌中 Trp 阻遏物水平的首次直接测量，并证实了 trpR 基因的自动调节性质。
A radioimmunoassay for the Trp repressor protein of Escherichia coli was developed with antisera raised against purified Trp repressor protein. This assay was used to directly measure the intracellular Trp repressor content in several E. coli K-12 and B/r strains. Repressor levels varied from 2.5- to 3-fold in response to L-tryptophan concentration in the growth medium (15 to 44 ng of repressor per mg of protein). Neither cell growth rate nor culture age had a significant effect on repressor concentrations within the cell. Addition of L-tryptophan to the growth medium resulted in lowered intracellular levels of Trp repressor. The absolute amounts of native Trp repressor molecules per cell varied between 120 and 375 dimers in the presence and absence of L-tryptophan in the culture medium, respectively. Assuming an intracellular volume of 7.3 microliters/10(10) E. coli cells, the Trp repressor concentration varied from 270 to 850 nM in response to extracellular tryptophan levels. These findings represent the first direct measurements of Trp repressor levels in E. coli and confirm the autoregulatory nature of the trpR gene.
aroH 的结构和调控，aroH 是大肠杆菌色氨酸抑制性 3-脱氧-D-阿拉伯-庚糖酸-7-磷酸合成酶的结构基因。
影响因子：
5.6
作者：
Zurawski,G;Gunsalus,RP;Brown,KD;Yanofsky,C
通讯作者：
Yanofsky,C
Trp阻遏蛋白控制其自身的结构基因。
影响因子：
5.6
作者：
Bogosian,G;Bertrand,K;Somerville,R
通讯作者：
Somerville,R
DOI：
10.1073/pnas.77.12.7117
发表时间：
1980-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
GUNSALUS, RP;YANOFSKY, C
通讯作者：
YANOFSKY, C