Traub P, Nelson W J
Eur J Cell Biol. 1981 Dec;26(1):61-7.
Several mammalian cell lines propagated in suspension and monolayer culture and some normal and cancerous tissues from rat, hamster and cat were screened for the presence of the Ca 2+ activated protease specific for the intermediate-sized filament protein vimentin. Gel permeation chromatography on Sephacryl S-300 of postnuclear supernatants, and sucrose density gradient centrifugation of extracts from Triton X-100-resistant residual cell structures revealed the presence of the enzyme in all cells and tissues tested. Its apparent molecular weight amounted to 100 000. Except in the cases of a spontaneous rat lung tumour and a rat hepatocellular carcinoma induced by diethylnitrosamine, most of the enzyme was released into the postnuclear supernatant during cell or tissue extraction, indicating that it is of cytoplasmic origin. There was no correlation between the enzyme level and the vimentin content of cells and tissues. Rat and hamster liver as well as cat kidney, in which vimentin has not been detected by polyacrylamide gel electrophoresis, were relatively rich in the Ca 2+ activated protease. The experimental results point at the widespread, if not general, occurrence of the enzyme in mammalian cells.
对几种在悬浮培养和单层培养中增殖的哺乳动物细胞系以及大鼠、仓鼠和猫的一些正常组织和癌组织进行了筛查，以检测是否存在对中间丝蛋白波形蛋白具有特异性的钙离子激活蛋白酶。对核后上清液进行Sephacryl S - 300凝胶渗透色谱分析，以及对来自抗Triton X - 100残留细胞结构的提取物进行蔗糖密度梯度离心，结果显示在所有测试的细胞和组织中均存在该酶。其表观分子量为100000。除了一例自发的大鼠肺肿瘤和一例由二乙基亚硝胺诱导的大鼠肝细胞癌外，在细胞或组织提取过程中，大部分酶释放到核后上清液中，这表明它起源于细胞质。酶水平与细胞和组织中的波形蛋白含量之间没有相关性。在聚丙烯酰胺凝胶电泳中未检测到波形蛋白的大鼠和仓鼠肝脏以及猫肾脏中，钙离子激活蛋白酶相对丰富。实验结果表明，该酶在哺乳动物细胞中即使不是普遍存在，也是广泛存在的。
