Haraguchi Y, Takiguchi M, Amaya Y, Kawamoto S, Matsuda I, Mori M
Proc Natl Acad Sci U S A. 1987 Jan;84(2):412-5. doi: 10.1073/pnas.84.2.412.
Arginase (EC 3.5.3.1) catalyzes the last step of the urea cycle in the liver of ureotelic animals. Inherited deficiency of the enzyme results in argininemia, an autosomal recessive disorder characterized by hyperammonemia. To facilitate investigation of the enzyme and gene structures and to elucidate the nature of the mutation in argininemia, we isolated cDNA clones for human liver arginase. Oligo(dT)-primed and random primer human liver cDNA libraries in lambda gt11 were screened using isolated rat arginase cDNA as a probe. Two of the positive clones, designated lambda hARG6 and lambda hARG109, contained an overlapping cDNA sequence with an open reading frame encoding a polypeptide of 322 amino acid residues (predicted Mr, 34,732), a 5'-untranslated sequence of 56 base pairs, a 3'-untranslated sequence of 423 base pairs, and a poly(A) segment. Arginase activity was detected in Escherichia coli cells transformed with the plasmid carrying lambda hARG6 cDNA insert. RNA gel blot analysis of human liver RNA showed a single mRNA of 1.6 kilobases. The predicted amino acid sequence of human liver arginase is 87% and 41% identical with those of the rat liver and yeast enzymes, respectively. There are several highly conserved segments among the human, rat, and yeast enzymes.
精氨酸酶（EC 3.5.3.1）催化排尿素动物肝脏中尿素循环的最后一步。该酶的遗传性缺乏会导致精氨酸血症，这是一种以高氨血症为特征的常染色体隐性疾病。为促进对该酶和基因结构的研究，并阐明精氨酸血症中突变的本质，我们分离了人肝脏精氨酸酶的cDNA克隆。以分离的大鼠精氨酸酶cDNA为探针，筛选了λgt11载体中的oligo(dT)引发的和随机引物的人肝脏cDNA文库。两个阳性克隆，命名为λhARG6和λhARG109，包含一个重叠的cDNA序列，其开放阅读框编码一个由322个氨基酸残基组成的多肽（预测的Mr为34,732），一个56个碱基对的5'-非翻译序列，一个423个碱基对的3'-非翻译序列，以及一个聚腺苷酸片段。在用携带λhARG6 cDNA插入片段的质粒转化的大肠杆菌细胞中检测到了精氨酸酶活性。对人肝脏RNA的RNA凝胶印迹分析显示有一条1.6千碱基的单一mRNA。人肝脏精氨酸酶的预测氨基酸序列与大鼠肝脏和酵母酶的氨基酸序列分别有87%和41%的同源性。在人、大鼠和酵母酶之间有几个高度保守的区段。
