Clarke S
J Biol Chem. 1976 Feb 25;251(4):950-61.
One of the major components of rat liver mitochondria detected by gel electrophoresis in sodium dodecyl sulfate is a 165,000 molecular weight polypeptide that makes up 15 to 20% of the total mitochondrial protein. This component appears to be a single molecular species. Evidence is presented here for the identification of this protein with the polypeptide chain of a urea cycle enzyme, carbamoylphosphate synthetase I (EC 2.7.2.5). The 165,000 molecular weight polypeptide was solubilized from mitochondria with Triton X-100 and purified to 90% homogeneity by DEAE-cellulose chromatography. This component co-migrated with carbamyl phosphate synthetase activity when mitochondrial proteins were separated by gel filtration or sucrose gradient centifugation. The identification of the 165,000 molecular weight polypeptide with this activity was also supported by the presence or absence of this protein in a variety of rat tissue mitochondria, in liver and kidney mitochondria from various ureotelic and nonureotelic species, and in fetal rat liver mitochondria.
通过十二烷基硫酸钠凝胶电泳检测到的大鼠肝脏线粒体的主要成分之一是一种分子量为165,000的多肽，它占线粒体总蛋白的15%至20%。该成分似乎是单一分子种类。本文提供了证据，证明该蛋白质与尿素循环酶氨甲酰磷酸合成酶I（EC 2.7.2.5）的多肽链相同。用Triton X-100从线粒体中溶解出分子量为165,000的多肽，并通过DEAE-纤维素色谱法将其纯化至90%的同质性。当通过凝胶过滤或蔗糖梯度离心分离线粒体蛋白时，该成分与氨甲酰磷酸合成酶活性共同迁移。在多种大鼠组织线粒体、来自各种排尿素和非排尿素物种的肝脏和肾脏线粒体以及胎鼠肝脏线粒体中该蛋白质的存在与否，也支持了将分子量为165,000的多肽与该活性进行鉴定。
