Allocati N, Aceto A, Cellini L, Masulli M, Dragani B, Petruzzelli R, Di Ilio C
Istituto di Medicina Sperimentale, Università G. D'Annunzio, Chieti, Italy.
FEMS Microbiol Lett. 1997;147(1):157-62. doi: 10.1111/j.1574-6968.1997.tb10236.x.
When Proteus mirabilis was cultured anaerobically in the presence of nitrate as terminal electron acceptor, a dramatic reduction of glutathione transferase production occurred. The analysis of the glutathione affinity purified materials in terms of substrate specificity, SDS-PAGE pattern, IEF pattern and immunoblotting revealed that a significantly different glutathione transferase pattern also occurred: two new glutathione transferase forms with an isoelectric point at pH 4.8 and 5.0 appeared. Their N-terminal amino acid sequence analysis as well as the ability to bind to a glutathione affinity column indicate that major differences between anaerobic and aerobic glutathione transferase forms are mainly located in the C-terminal region of the primary structure. In contrast, no significant changes occurred in the production of glutathione transferase isoenzymes when P. mirabilis was grown anaerobically in the absence of a terminal electron acceptor. These results support the idea that bacterial glutathione transferase expression is not strictly related to the absence of oxygen stress.
当奇异变形杆菌在以硝酸盐作为末端电子受体的条件下进行厌氧培养时，谷胱甘肽转移酶的产量会显著降低。对经谷胱甘肽亲和纯化的物质进行底物特异性、SDS - PAGE图谱、IEF图谱和免疫印迹分析发现，谷胱甘肽转移酶的图谱也出现了显著差异：出现了两种新的谷胱甘肽转移酶形式，其等电点分别为pH 4.8和5.0。它们的N端氨基酸序列分析以及与谷胱甘肽亲和柱结合的能力表明，厌氧型和好氧型谷胱甘肽转移酶形式之间的主要差异主要位于一级结构的C端区域。相比之下，当奇异变形杆菌在没有末端电子受体的情况下进行厌氧培养时，谷胱甘肽转移酶同工酶的产量没有显著变化。这些结果支持了细菌谷胱甘肽转移酶表达与缺氧应激并无严格关联的观点。
