番茄（Lycopersicon esculentum）叶片中两种谷氨酸合酶形式的分离。

Separation of two forms of glutamate synthase in leaves of tomato (Lycopersicon esculentum).

作者信息

Avila C, Cánovas F, Núñez de Castro I, Valpuesta V

出版信息

Biochem Biophys Res Commun. 1984 Aug 16;122(3):1125-30. doi: 10.1016/0006-291x(84)91208-7.

Abstract

Two forms of glutamate synthase, one dependent on NAD(P)H, and the other on ferredoxin, have been completely separated by ionic exchange chromatography on DEAE cellulose. The NAD(P)H dependent enzyme was further purified by affinity chromatography with Blue Sepharose, showing Km values of 0.5 mM, 0.3 mM and 1.7 microM for glutamine, 2-oxoglutarate and NADH, respectively. Ferredoxin dependent enzyme was also purified to electrophoretic homogeneity; the Km values were 0.5 mM, 0.2 mM and 0.2 microM for glutamine, 2-oxoglutarate and ferredoxin, respectively. These results support the glutamine synthetase - glutamate synthase pathway for nitrogen assimilation.

摘要

通过在DEAE纤维素上进行离子交换色谱法，已将两种形式的谷氨酸合酶完全分离，一种依赖于NAD(P)H，另一种依赖于铁氧还蛋白。依赖于NAD(P)H的酶通过用蓝色琼脂糖凝胶进行亲和色谱法进一步纯化，其对谷氨酰胺、2-氧代戊二酸和NADH的Km值分别为0.5 mM、0.3 mM和1.7 microM。依赖于铁氧还蛋白的酶也被纯化至电泳纯；其对谷氨酰胺、2-氧代戊二酸和铁氧还蛋白的Km值分别为0.5 mM、0.2 mM和0.2 microM。这些结果支持了谷氨酰胺合成酶-谷氨酸合酶途径用于氮同化。