GLUTAMATE-DEHYDROGENASE FROM THE THERMOACIDOPHILIC ARCHAEBACTERIUM SULFOLOBUS-SOLFATARICUS
GLUTAMATE-DEHYDROGENASE FROM THE THERMOACIDOPHILIC ARCHAEBACTERIUM SULFOLOBUS-SOLFATARICUS
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DOI：
10.1111/j.1432-1033.1991.tb15837.x
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发表时间：
1991-03-14
期刊：
影响因子：
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通讯作者：
SCANDURRA, R
中科院分区：
文献类型：
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作者：
CONSALVI, V;CHIARALUCE, R;SCANDURRA, R
从嗜热嗜酸古细菌硫磺硫化叶菌（Sulfolobus solfataricus）中纯化了一种NAD（P）依赖性谷氨酸脱氢酶。该酶是一种六聚体（亚基质量45 kDa），当进行凝胶过滤时，其解离成较低的缔合状态。纯化的酶的等电聚焦分析表明，pI为5.7，偶尔揭示微观异质性。该酶对天然底物2-酮戊二酸和L-谷氨酸具有严格特异性，但对NADH和NADPH都具有活性。S. Solfataricus谷氨酸脱氢酶显示出高度的热稳定性（在80 ℃下，半衰期为15小时），其严格依赖于蛋白质浓度。在该古细菌中发现非常高水平的谷氨酸脱氢酶，这表明2-酮戊二酸和氨转化为谷氨酸对该细菌中的氮代谢至关重要。
An NAD(P)-dependent glutamate dehydrogenase was purified to homogeneity from the thermoacidophilic archaebacterium Sulfolobus solfataricus. The enzyme is a hexamer (subunit mass 45 kDa) which dissociates into lower state of association when submitted to gel filtration. Isoelectric focusing analysis of the purified enzyme showed a pI of 5.7 and occasionally revealed microheterogeneity. The enzyme is strictly specific for the natural substrates 2-oxoglutarate and L-glutamate, but is active with both NADH and NADPH. S. solfataricus glutamate dehydrogenase revealed a high degree of thermal stability (at 80-degrees-C the half-life was 15 h) which was strictly dependent on the protein concentration. Very high levels of glutamate dehydrogenase were found in this archaebacterium which suggests that the conversion of 2-oxoglutarate and ammonia to glutamate is of central importance to the nitrogen metabolism in this bacterium.