GLUTAMATE SYNTHASE - PROPERTIES OF REDUCED NICOTINAMIDE ADENINE DINUCLEOTIDE-DEPENDENT ENZYME FROM SACCHAROMYCES-CEREVISIAE
GLUTAMATE SYNTHASE - PROPERTIES OF REDUCED NICOTINAMIDE ADENINE DINUCLEOTIDE-DEPENDENT ENZYME FROM SACCHAROMYCES-CEREVISIAE
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DOI：
10.1128/jb.118.1.89-95.1974
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发表时间：
1974-01-01
影响因子：
3.2
通讯作者：
LARIMORE, F
中科院分区：
文献类型：
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作者：
ROON, RJ;EVEN, HL;LARIMORE, F
从酿酒酵母粗提物中检测到一种依赖NADH的还原型谷氨酸合成酶，并对其进行了部分纯化。该酶对NADH、谷氨酰胺和α-酮戊二酸(Km值分别为2.6μM、1.0 mM和14 0μM)具有专一性，最适pH为7.1~7.7。该反应的化学计量比为每消耗1摩尔谷氨酰胺合成2摩尔谷氨酸。根据谷氨酸合酶在琼脂糖凝胶和离子交换层析中的底物要求和行为，可以将谷氨酸合酶与酵母的谷氨酸脱氢酶区分开来。谷氨酸合成酶的比活性变化，发生在生长介质的变化，在性质上类似于观察到的烟酰胺腺嘌呤二核苷酸磷酸依赖(合成代谢)谷氨酸脱氢酶。
A reduced nicotinamide adenine dinucleotide (NADH)-dependent glutamate synthase has been detected and partially purified from crude extracts ofSaccharomyces cerevisiae. The enzyme is specific for NADH, glutamine, and α-ketoglutarate (Kmvalues of 2.6 μM, 1.0 mM, and 140 μM, respectively) and has a pH optimum between 7.1 and 7.7. The stoichiometry of the reaction has been determined as 2 mol of glutamate synthesized per mol of glutamine consumed. Glutamate synthase can be distinguished from either of the glutamate dehydrogenases of yeast on the basis of its substrate requirements and behavior during agarose gel and ion exchange chromatography. Variations in the specific activity of glutamate synthase, which occur in response to changes in the growth medium, are similar in character to those observed with the nicotinamide adenine dinucleotide phosphate-dependent (anabolic) glutamate dehydrogenase.