Regulation of Bacillus subtilis glutamine phosphoribosylpyrophosphate amidotransferase inactivation in vivo.
Regulation of Bacillus subtilis glutamine phosphoribosylpyrophosphate amidotransferase inactivation in vivo.
复制标题
体内枯草芽孢杆菌谷氨酰胺磷酸核糖焦磷酸酰胺转移酶失活的调节。
DOI：
10.1128/jb.153.2.937-949.1983
复制
发表时间：
1983
影响因子：
3.2
通讯作者：
Switzer,RL
中科院分区：
文献类型：
--
作者：
Bernlohr,DA;Switzer,RL
谷氨酰胺磷酸核糖焦磷酸酰胺转移酶在生长的细胞中是稳定的，但在饥饿或饥饿处理的细胞中以不同的速率在氧依赖性过程中失活。根据对纯化酶的研究，我们建议（D. A. Bernlohr和R.L. Switzer，Biochemistry 20：5675-5681，1981），体内失活受底物稳定化以及稳定化（AMP）和去稳定化（GMP、GDP和ADP）核苷酸之间的竞争调节。通过在酰胺转移酶的稳定性变化的培养条件下测量这些代谢物的细胞内水平来测试该提议。结果表明，酰胺转移酶在体内的稳定性不能用体外观察到的简单相互作用来解释。与生长细胞中酶的稳定性相关的代谢物水平在其他条件下不赋予稳定性，如氨饥饿或葡萄糖饥饿细胞的再喂养。这些数据表明，以前未被识别的事件，可能是一个共价修饰的酰胺转移酶，需要标记的氧依赖性失活酶。
Glutamine phosphoribosylpyrophosphate amidotransferase is stable in growing cells, but is inactivated in an oxygen-dependent process at various rates in starving or antibiotic-treated cells. On the basis of studies of the purified enzyme, we suggested (D.A. Bernlohr and R.L. Switzer, Biochemistry 20:5675-5681, 1981) that the inactivation in vivo was regulated by substrate stabilization and a competition between stabilizing (AMP) and destabilizing (GMP, GDP, and ADP) nucleotides. This proposal was tested by measuring the intracellular levels of these metabolites under cultural conditions in which the stability of the amidotransferase varied. The results established that the stability of amidotransferase in vivo cannot be explained by the simple interactions observed in vitro. Metabolite levels associated with stability of the enzyme in growing cells did not confer stability under other conditions, such as ammonia starvation or refeeding of glucose-starved cells. The data suggest that a previously unrecognized event, possibly a covalent modification of amidotransferase, is required to mark the enzyme for oxygen-dependent inactivation.