Aleĭnikova T D, Vasil'ev V B, Monakhov N K, Shavlovskiĭ M M
Biokhimiia. 1987 Oct;52(10):1600-7.
The synthesis and secretion of ceruloplasmin (Cp) by isolated rat hepatocytes were investigated. Cp released by liver cells appeared to have properties similar to those of the blood-circulating protein, i. e. Mr, oxidase activity, immunological specificity and the peptide set of tryptic fingerprints. The polypeptides with Mr of 130,000, 65,000, 48,000 and 18,000 were revealed in Cp isolated from the incubation medium. These results suggest the susceptibility of the single-chain protein molecule (Mr 130,000) to limited proteolysis which is accomplished by the proteases released from the cells. When fresh serum was added to the incubation medium, the proteolytic degradation of Cp proceeded at a much slower rate, which led to an increase in the content of excreted polypeptides with Mr 130,000. The secretion was strongly diminished by the addition of colchicine to the medium. The time of Cp molecule synthesis on membrane-bound polyribosomes (3.5 min) was determined.
对分离出的大鼠肝细胞中铜蓝蛋白（Cp）的合成与分泌进行了研究。肝细胞释放的Cp似乎具有与血液循环中的蛋白质相似的特性，即分子量、氧化酶活性、免疫特异性和胰蛋白酶指纹图谱的肽组。从培养液中分离出的Cp中发现了分子量为130,000、65,000、48,000和18,000的多肽。这些结果表明单链蛋白质分子（分子量130,000）易受细胞释放的蛋白酶介导的有限蛋白水解作用的影响。当向培养液中加入新鲜血清时，Cp的蛋白水解降解速度要慢得多，这导致分泌出的分子量为130,000的多肽含量增加。向培养液中添加秋水仙碱会使分泌大幅减少。测定了膜结合多核糖体上Cp分子的合成时间（3.5分钟）。
