Wong P T, McGeer E G, McGeer P L
J Neurochem. 1981 Feb;36(2):501-5. doi: 10.1111/j.1471-4159.1981.tb01620.x.
A radiometric assay for ornithine aminotransferase was developed using [1-14C]alpha-ketoglutarate as the labeled substrate and glutamate decarboxylation as a linking step. This assay gives near total measurement of ornithine aminotransferase activities that are, respectively, about 1.5 and 10 times larger than those obtained by the spectrophotometric assay and the radiometric assay using [1-14C]ornithine. It is also the most sensitive of the three assay procedures. Consistent with previous reports, brain ornithine aminotransferase was found to be present predominantly in synaptosomes. Regional distribution of the enzyme correlated with that of the high-affinity uptake of glutamate, but not with the distribution of glutamate decarboxylase. Ornithine aminotransferase may be responsible for the synthesis of glutamate in glutamatergic neurons but it is clearly not localized exclusively in such neurons.
开发了一种鸟氨酸转氨酶的放射性测定法，使用[1-14C]α-酮戊二酸作为标记底物，并以谷氨酸脱羧作为连接步骤。该测定法几乎能全面测量鸟氨酸转氨酶的活性，分别比分光光度法和使用[1-14C]鸟氨酸的放射性测定法所测得的活性大约高1.5倍和10倍。它也是这三种测定方法中最灵敏的。与先前的报道一致，发现脑鸟氨酸转氨酶主要存在于突触体中。该酶的区域分布与谷氨酸的高亲和力摄取相关，但与谷氨酸脱羧酶的分布无关。鸟氨酸转氨酶可能负责谷氨酸能神经元中谷氨酸的合成，但显然并非仅局限于此类神经元。
