Abe T, Ishiguro S, Tamai M
Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Japan.
Jpn J Ophthalmol. 1994;38(1):16-23.
In the present study, we investigated the enzymatical properties of the heat-labile and heat-stable glutamate dehydrogenases (GDHs) from the bovine retina and human leukocytes. Retinal GDHs were mitochondrial enzymes with an optimal pH of 7.5. Heat-labile (membrane-associated form) and heat-stable (soluble form) GDHs were found in the bovine retina as well as in the human leukocytes. At least 5 GDH isoenzymes were found in the retina and leukocytes by nondenaturing polyacrylamide gel electrophoresis. After heat treatment, the high-speed pellet obtained from centrifugation of the human leukocytes at 100,000 x g retained the 3 smaller isoenzymes but had lost the 2 larger isoenzymes. Both heat-labile and heat-stable GDH were found in the neuroretina, retinal pigment epithelium and optic nerve with high activities. Our results suggest that these tissues may be the main active sites of the GDH deficiency.
在本研究中，我们研究了来自牛视网膜和人白细胞的热不稳定和热稳定谷氨酸脱氢酶（GDHs）的酶学性质。视网膜GDHs是线粒体酶，最适pH为7.5。在牛视网膜以及人白细胞中发现了热不稳定（膜结合形式）和热稳定（可溶性形式）的GDHs。通过非变性聚丙烯酰胺凝胶电泳在视网膜和白细胞中发现了至少5种GDH同工酶。热处理后，以100,000×g离心人白细胞得到的高速沉淀保留了3种较小的同工酶，但失去了2种较大的同工酶。在神经视网膜、视网膜色素上皮和视神经中均发现热不稳定和热稳定的GDH具有高活性。我们的结果表明，这些组织可能是GDH缺乏的主要活性部位。
