Movsesian S G, Avetisian S G, Ekizian N G
Vopr Biokhim Mozga. 1978;13:228-47.
The present report concerns the study of the catalytic properties and the coenzyme affinity of glutamate dehydrogenase (GDH) and its isoenzymes in various preparations of the brain and liver as well as the different regulatory mechanisms controlling the ratio of the rates of biogenesis and breakdown of glutamate (Glu). The investigations carried out showed that GDH activity of various preparations of brain and liver (crystalline enzymes, cellular extracts and mitochondria) are markedly different from each other by their catalytic and regulatory properties as well as by their coenzyme activity. The data obtained make us conclude that nicotinamide-hypoxanthine-nucleotide (deaminoNAD) is a more effective coenzyme in the oxidative deamination of Glu, than other piridine nucleotides (NAD, NADP, deamino-NADP). It is supposed that in the formation of ammonia and amino acids in brain and especially liver, together with other known mechanisms an important role may be ascribed to the process of transdeamination. In this aspect, as a co-factor of oxidative deamination of Glu deamino-NAD (D-NAD) is thought to be of significant importance.
本报告涉及对谷氨酸脱氢酶（GDH）及其同工酶在脑和肝的各种制剂中的催化特性和辅酶亲和力的研究，以及控制谷氨酸（Glu）生物合成和分解速率之比的不同调节机制。所进行的研究表明，脑和肝的各种制剂（结晶酶、细胞提取物和线粒体）中的GDH活性在催化和调节特性以及辅酶活性方面彼此明显不同。所获得的数据使我们得出结论，烟酰胺 - 次黄嘌呤 - 核苷酸（脱氨基NAD）在Glu的氧化脱氨反应中比其他吡啶核苷酸（NAD、NADP、脱氨基 - NADP）是更有效的辅酶。据推测，在脑尤其是肝中氨和氨基酸的形成过程中，除了其他已知机制外，转氨基作用过程可能起重要作用。在这方面，作为Glu氧化脱氨的辅助因子，脱氨基NAD（D - NAD）被认为具有重要意义。
