Quantitative renaturation from a guanidine-denatured state of the SecA dimer, a 200 KDa protein involved in protein secretion in Escherichia coli.
Quantitative renaturation from a guanidine-denatured state of the SecA dimer, a 200 KDa protein involved in protein secretion in Escherichia coli.
复制标题
SecA 二聚体（一种参与大肠杆菌蛋白质分泌的 200 KDa 蛋白质）的胍变性状态的定量复性。
DOI：
10.1016/0006-291x(90)91578-g
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发表时间：
1990
影响因子：
3.1
通讯作者：
S. Mizushima
中科院分区：
文献类型：
--
作者：
A. Shinkai;M. Akita;S. Matsuyama;S. Mizushima
SECA是大肠杆菌蛋白质分泌机制的重要组成部分。用稀释法和透析法对在6M盐酸胍中变性的SeCA进行了定量复性。复性后的SeCA的CD光谱、色氨酸残基的荧光光谱和二聚体结构与天然SeCA相同。在与ATP和存储前期蛋白的相互作用以及体外易位方面，它与天然的SecA一样具有活性。SecA-N95缺少羧基末端的70个氨基酸残基，包括四个半胱氨酸残基中的三个，但在体外转位方面仍与完整的SecA一样活跃，也从胍溶液中复性为活性形式。此外，在1 mM二硫苏糖醇存在下，塞卡的复性也发生了。结果表明，二硫键，包括分子内和分子间的二硫键，在SecA分子的折叠和功能中不起作用。
SecA is an essential component of the protein secretory machinery of Escherichia coli. SecA denatured in 6 M guanidine hydrochloride was quantitatively renatured through dilution and dialysis. The renatured SecA was the same as native SecA as to the CD spectrum, fluorescence spectrum for tryptophan residues and dimeric structure. It was as functionally active as native SecA as to interactions with ATP and presecretory proteins, and in vitro translocation. SecA-N95, which lacks the carboxyl-terminal 70 amino acid residues including three of four cysteine residues and yet is as active as intact SecA as to in vitro translocation, was also renatured to an active form from the guanidine solution. Furthermore, the renaturation of SecA took place in the presence of 1 mM dithiothreitol. It is concluded that disulfide bridges, both intra-and intermolecular ones, do not play a role in the folding and functioning of the SecA molecule.