Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences - Branch of Perm Federal Research Center, Ural Branch of the Russian Academy of Sciences, Perm, Russia.
Bull Exp Biol Med. 2024 Apr;176(6):791-795. doi: 10.1007/s10517-024-06110-2. Epub 2024 Jun 19.
E. coli exposure to ciprofloxacin disturbs cysteine homeostasis; an increase in the intracellular concentration of cysteine is dangerous due to its ability to enhance ROS generation. Unlike wild-type bacteria, in which the cysteine content did not exceed the control level, cells of the gshA mutant lacking glutathione are characterized by increased concentration of intracellular cysteine in proportion to the concentrations of the antibiotic, despite the intensive export of cysteine into the medium. At low concentrations of ciprofloxacin, the mutant strain formed half as many colonies as the parent strain in the survival test. These findings attest to the important role of the incorporation of excess cysteine into glutathione as one of the mechanisms of cysteine homeostasis during the stress response to antibiotic.
大肠杆菌暴露于环丙沙星会扰乱半胱氨酸稳态；由于半胱氨酸能够增强 ROS 的产生，因此细胞内半胱氨酸浓度的增加是危险的。与野生型细菌不同，在缺乏谷胱甘肽的 gshA 突变体中，尽管半胱氨酸被强烈地输出到培养基中，但细胞内半胱氨酸的浓度仍会随着抗生素浓度的增加而增加，而其半胱氨酸含量不会超过对照水平。在低浓度的环丙沙星下，突变株在生存试验中形成的菌落数是亲株的一半。这些发现证明了将过量的半胱氨酸掺入谷胱甘肽作为抗生素应激反应中半胱氨酸稳态的机制之一的重要作用。
