Hornby D P, Engel P C
J Gen Microbiol. 1984 Sep;130(9):2385-94. doi: 10.1099/00221287-130-9-2385.
Glutamate dehydrogenase (L-glutamate:NAD+ oxidoreductase (deaminating); EC 1.4.1.2) has been purified from Peptostreptococcus asaccharolyticus in a single step using dye-ligand chromatography. The enzyme (GDH) was present in high yields and was stabilized in crude extracts. A subunit molecular weight of 49000 +/- 500 was determined by SDS polyacrylamide gel electrophoresis and six bands were obtained after cross-linking the subunits with dimethyl suberimidate. This bacterial GDH was predominantly NAD+-linked, but was able to utilize both NADP+ and NADPH at 4% of the rates with NAD+ and NADH, respectively. An investigation of the amino acid specificity revealed some similarities with GDH from mammalian sources and some clear differences. The values of apparent Km for the substrates ammonia, 2-oxoglutarate, NADH, NAD+ and glutamate were 18.4, 0.82, 0.066, 0.031 and 6 mM, respectively. The P. asaccharolyticus GDH was not regulated by purine nucleotides, but was subject to strong inhibition with increasing ionic strength.
已使用染料配体色谱法从解糖消化链球菌中一步纯化出谷氨酸脱氢酶（L-谷氨酸：NAD⁺氧化还原酶（脱氨基）；EC 1.4.1.2）。该酶（GDH）产量高，且在粗提物中稳定。通过SDS聚丙烯酰胺凝胶电泳测定亚基分子量为49000±500，用辛二酸二甲酯交联亚基后得到六条带。这种细菌GDH主要与NAD⁺相连，但分别以NAD⁺和NADH速率的4%利用NADP⁺和NADPH。对氨基酸特异性的研究揭示了与哺乳动物来源的GDH有一些相似之处和一些明显差异。底物氨、2-氧代戊二酸、NADH、NAD⁺和谷氨酸的表观Km值分别为18.4、0.82、0.066、0.031和6 mM。解糖消化链球菌GDH不受嘌呤核苷酸调节，但随着离子强度增加受到强烈抑制。
