Kvamme E, Nissen-Meyer L S H, Roberg B A, Torgner I Aa
Neurochemical Section, Department of Biochemistry, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
Neurochem Res. 2008 Jul;33(7):1341-5. doi: 10.1007/s11064-008-9589-9. Epub 2008 Feb 15.
A novel form of phosphate activated glutaminase (PAG), catalyzing the synthesis of glutamate from glutamine, has been detected in cultured astrocytes and SH-SY5Y neuroblastoma cells. This enzyme form is different from that of the kidney and liver isozymes. In these cells we found high enzyme activity, but no or very weak immunoreactivity against the kidney type of PAG, and no immunoreactivity against the liver type. PAG was also investigated in brain under pathological conditions. In patients with Down's syndrome the immunoreactivity in the frontoparietal cortex was significantly reduced. The findings leading to our conclusion of a functionally active PAG on the outer face of the inner mitochondrial membrane are discussed, and a model is presented.
在培养的星形胶质细胞和SH-SY5Y神经母细胞瘤细胞中检测到一种新型的磷酸激活谷氨酰胺酶（PAG），它催化谷氨酰胺合成谷氨酸。这种酶形式与肾脏和肝脏的同工酶不同。在这些细胞中，我们发现酶活性很高，但对肾脏型PAG的免疫反应性没有或非常弱，对肝脏型则没有免疫反应性。还对病理条件下的大脑中的PAG进行了研究。在唐氏综合征患者中，额顶叶皮质的免疫反应性显著降低。讨论了导致我们得出线粒体内膜外表面存在功能活跃的PAG这一结论的研究结果，并提出了一个模型。
