Properties of Ca2+-activated protease specific for the intermediate-sized filament protein vimentin in Ehrlich-ascites-tumour cells.
Properties of Ca2+-activated protease specific for the intermediate-sized filament protein vimentin in Ehrlich-ascites-tumour cells.
复制标题
艾利希腹水肿瘤细胞中中等大小丝状蛋白波形蛋白特异的 Ca2 激活蛋白酶的特性。
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
P. Traub
中科院分区：
文献类型：
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作者：
W. Nelson;P. Traub
描述了一种Ca 2+激活的中性蛋白酶，当对各种天然蛋白质进行测试时，该蛋白酶似乎对波形蛋白具有特异性，波形蛋白是埃里希腹水肿瘤细胞中中等大小（7- 11 nm）细丝的58，000-Mr亚基蛋白。其他类别的中等大小的细丝的蛋白质亚基已被测试;神经丝蛋白和胶质细胞酸性蛋白不降解，但骨骼素，在平滑肌中的中等大小的细丝的亚基蛋白，降解。发现蛋白酶与埃里希腹水肿瘤细胞的抗洗涤剂细胞骨架相关;除波形蛋白外，存在于该结构中的蛋白质不被降解。蛋白酶被Ca 2+和Sr 2+激活，但不被测试的其他二价阳离子激活：激活所需的Ca 2+浓度为10 μ M。最适pH为7.5 ~ 8.0，KCl浓度为100 mM，能被1-氯-3-对甲苯磺酰氨基-7-氨基-L-2-庚酮盐酸盐和L-1-对甲苯磺酰氨基-2-苯乙基氯甲基酮抑制，但不被大豆胰蛋白酶抑制剂抑制，苯甲基磺酰氟对该蛋白酶有中等抑制作用。蛋白酶的高底物特异性表明它可能在埃里希腹水肿瘤细胞中的波形蛋白中等大小的丝蛋白周转中发挥作用。
A Ca2+-activated neutral protease is described which, when tested against various native proteins, appears to be specific for vimentin, the 58,000-Mr subunit protein of intermediate-sized (7--11 nm) filaments in Ehrlich-ascites-tumour cells. The protein subunits of other classes of intermediate-sized filaments have been tested; neurofilament protein and glial fibrillary acidic protein are not degraded, however skeletin, the subunit protein of intermediate-sized filaments in smooth muscle, is degraded. The protease is found associated with the detergent-resistant cytoskeleton of Ehrlich-ascites-tumour cells; proteins, other than vimentin, present in this structure are not degraded. The protease is activated by Ca2+ and Sr2+ but not by other divalent cations tested: the Ca2+ concentration required for activation is 10 microM. The pH optimum is between pH 7.5 and 8.0, and the KCl concentration required for optimal activity is 100 mM. The protease is inhibited by 1-chloro-3-tosylamido-7-amino-L-2-heptanone hydrochloride and L-1-tosylamido-2-phenylethyl chloromethyl ketone but not by soybean trypsin inhibitor; inhibition by phenylmethylsulphonyl fluoride is moderate. The high substrate specificity of the protease suggests it may play a role in vimentin intermediate-sized filament protein turnover in Ehrlich-ascites-tumour cells.