Shugalei V S, Chupich Z H, Iapundzhich I, Rakich L
Biokhimiia. 1977 Jan;42(1):67-73.
Distribution of arginase and gamma-guanidine-butyrate-ureohydrolase in seven brain sections is studied. Specific activity of arginase in brain sections is 0.063-0.117 and of gamma-guanidine-butyrate-ureohydrolase -- 0.042-0.050 mcmoles of urea per 1 mg of protein for 30 min. Cortex and cerebellum neurons have the same arginase activity (0.12 mcmole/mg). Specific arginase activity in glial cerebellum cells is 3 times as much as in cortex glial cells (0.20 and 0.07 mcmole/mg respectively). The activity of gamma-guanidine-butyrate-ureohydrolase in glial cell is higher than in neurons. Subcellular distribution of both enzymes is studied in those brain sections where their activity is maximal. In cerebellum both enzymes were tested, in cortex -- gamma-guanidine-butyrate-ureohydrolase, in thalamus -- arginase. The highest specific arginase activity is found in cytoplasmic, microsomic and synaptosomic fractions. Gamma-Guanidine-butyrate-ureohydrolase is concentrated in cytoplasmic and synaptosomic fractions. Possible correlation of gamma-aminobutyric acid metabolism and participation of brain arginase in regulation of protein biosynthesis are discussed.
研究了精氨酸酶和γ-胍基丁酸尿素水解酶在七个脑区的分布情况。脑区中精氨酸酶的比活性为每毫克蛋白质每分钟0.063 - 0.117微摩尔尿素，γ-胍基丁酸尿素水解酶的比活性为每毫克蛋白质30分钟0.042 - 0.050微摩尔尿素。皮质和小脑神经元的精氨酸酶活性相同（0.12微摩尔/毫克）。小脑神经胶质细胞中的精氨酸酶比活性是皮质神经胶质细胞中的3倍（分别为0.20和0.07微摩尔/毫克）。神经胶质细胞中γ-胍基丁酸尿素水解酶的活性高于神经元。在这两种酶活性最高的脑区研究了它们的亚细胞分布。在小脑中检测了这两种酶，在皮质中检测了γ-胍基丁酸尿素水解酶，在丘脑中检测了精氨酸酶。在细胞质、微粒体和突触体组分中发现了最高的精氨酸酶比活性。γ-胍基丁酸尿素水解酶集中在细胞质和突触体组分中。讨论了γ-氨基丁酸代谢的可能相关性以及脑精氨酸酶在蛋白质生物合成调节中的作用。
