Refolding and unfolding kinetics of the equilibrium folding intermediate of apomyoglobin
Refolding and unfolding kinetics of the equilibrium folding intermediate of apomyoglobin
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DOI：
10.1038/nsb0796-613
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发表时间：
1996-07-01
期刊：
影响因子：
--
通讯作者：
Baldwin, RL
中科院分区：
文献类型：
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作者：
Jamin, M;Baldwin, RL
关于蛋白质折叠中稳定中间体形成的动力学过程知之甚少：它们的折叠是高度合作（双态）还是弱合作是有争议的。在这里，我们报告的折叠和展开动力学的pH 4-稳定的中间体（I-1）的脱辅基肌红蛋白是可测量的，在毫秒的时间范围内，当通过停流测量色氨酸荧光监测。动力学证实，折叠的I-1是强烈的合作，但有一个突发阶段（丢失幅度）在展开。如果I-1去折叠的更快步骤可以通过合适的快速反应方法直接测量，它们将提供关于折叠转变性质的信息。
Little is known about the kinetic process in which stable intermediates in protein folding are formed: whether their folding is highly cooperative (two-state) or weakly cooperative is controversial. We report here that the folding and unfolding kinetics of the pH 4-stable intermediate (I-1) of apomyoglobin are measurable, in the millisecond time range, when monitored by stopped-flow measurements of tryptophan fluorescence. The kinetics confirm that folding of I-1 is strongly cooperative, but there is a burst phase (missing amplitude) in unfolding. If the faster steps in unfolding of I-1 can be measured directly by suitable fast-reaction methods, they will give information about the nature of the folding transition.