Kinetics of Folding and Membrane Insertion of a β-Barrel Membrane Protein (*)
Kinetics of Folding and Membrane Insertion of a β-Barrel Membrane Protein (*)
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DOI：
10.1074/jbc.270.47.28199
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发表时间：
1995-11
期刊：
影响因子：
--
通讯作者：
T. Surrey;F. Jähnig
中科院分区：
文献类型：
--
作者：
T. Surrey;F. Jähnig
我们研究了大肠杆菌外膜蛋白OmpA的折叠和膜插入动力学。在天然结构中，其膜插入结构域形成β-桶。蛋白质在水/尿素中以溶解形式展开，通过稀释尿素和同时加入脂质囊泡诱导重折叠。沿着折叠途径可以区分出三个过渡沿着。它们的特征时间低于一秒，在分钟范围内，在一小时范围内。快速过程对应于从在水/尿素中的未折叠状态到在水中的错误折叠状态的转变，适度缓慢过程对应于从膜中的错误折叠状态到部分折叠状态的转变，并且缓慢过程对应于从部分折叠状态到天然状态的转变。膜中的部分折叠状态被解释为可溶性蛋白质的熔融球状态的类似物。
We have studied the kinetics of folding and membrane insertion of the outer membrane protein OmpA of Escherichia coli. In the native structure, its membrane-inserted domain forms a β-barrel. The protein was unfolded in solubilized form in water/urea, and refolding was induced by dilution of urea and simultaneous addition of lipid vesicles. Three transitions along the folding pathway could be distinguished. Their characteristic times lie below a second, in the range of minutes, and in the range of an hour. The fast process corresponds to the transition from the unfolded state in water/urea to a misfolded state in water, the moderately slow process to a transition from the misfolded state to a partially folded state in the membrane, and the slow process to the transition from the partially folded to the native state. The partially folded state in the membrane is interpreted as the analogue of the molten globule state of soluble proteins.