GLUTATHIONE BIOSYNTHESIS IN ESCHERICHIA-COLI K-12 - PROPERTIES OF ENZYMES AND REGULATION
GLUTATHIONE BIOSYNTHESIS IN ESCHERICHIA-COLI K-12 - PROPERTIES OF ENZYMES AND REGULATION
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DOI：
10.1016/0304-4165(75)90205-6
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发表时间：
1975-01-01
期刊：
影响因子：
--
通讯作者：
BERENDS, W
中科院分区：
文献类型：
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作者：
APONTOWEIL, P;BERENDS, W
在粗制无细胞提取物中研究了大肠杆菌 K 12 中谷胱甘肽的合成。已经确定了两种合成酶、γ-谷氨酰半胱氨酸合成酶和谷胱甘肽合成酶的底物的最适pH值和表观Km值。发现γ-谷氨酰半胱氨酸合成酶的活性大约是谷胱甘肽合成酶的两倍。在生长培养物中，GSH 水平显着增加，在稳定生长期每毫升细胞沉淀中 GSH 水平显着增加，达到 6.6 μmol。 GSSG 未检测到。酶的水平保持恒定，表明谷胱甘肽生物合成至少在开始时取决于组分氨基酸的可用性。该通路由反馈抑制而非抑制控制。
The synthesis of glutathione inEscherichia coliK 12 was studied in crude, cell-free extracts. The pH optima and the apparentKmvalues for the substrates have been determined for both synthesizing enzymes, γ-glutamylcysteine synthetase and glutathione synthetase.γ-Glutamylcysteine synthetase was found to be approximately twice as active as glutathione synthetase. In a growing culture, the level of GSH showed a considerable increase up to 6.6 μmol per ml cell pellet in the stationary growth phase. GSSG was not detectable. The levels of the enzymes remained constant, indicating that glutathione biosynthesis depends at least in the beginning on the availability of the component amino acids. The pathway is controlled by feedback inhibition and not by repression.