Palaiologos G, Hertz L, Schousboe A
Department of Biochemistry A, Panum Institute, University of Copenhagen, Denmark.
J Neurochem. 1988 Jul;51(1):317-20. doi: 10.1111/j.1471-4159.1988.tb04872.x.
Based on the selective inhibition of glutamate release in cerebellar granule cells in primary cultures by the aspartate aminotransferase inhibitor, aminooxyacetic acid, and by the ketodicarboxylate carrier inhibitor, phenylsuccinate, a novel model for synthesis of transmitter glutamate is suggested: Glutamate is formed from glutamine in the mitochondrial intramembrane space by phosphate-activated glutaminase, transported across the inner membrane in exchange with aspartate, transaminated in the matrix to alpha-ketoglutarate, which via the ketodicarboxylate carrier is transferred to the cytoplasm, and transaminated to form transmitter glutamate. Such a mechanism would explain the functional role of aspartate aminotransferase in glutamatergic neurons.
基于天冬氨酸转氨酶抑制剂氨氧基乙酸以及酮二羧酸载体抑制剂苯基琥珀酸对原代培养的小脑颗粒细胞中谷氨酸释放的选择性抑制作用，提出了一种新型的递质谷氨酸合成模型：谷氨酸由谷氨酰胺在线粒体内膜间隙通过磷酸激活的谷氨酰胺酶形成，与天冬氨酸交换后穿过内膜转运至基质，在基质中转氨基生成α-酮戊二酸，α-酮戊二酸通过酮二羧酸载体转运至细胞质，再转氨基形成递质谷氨酸。这样一种机制将解释天冬氨酸转氨酶在谷氨酸能神经元中的功能作用。
