Kinetics of actin unfolding induced by guanidine hydrochloride
Kinetics of actin unfolding induced by guanidine hydrochloride
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DOI：
10.1021/bi015548c
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发表时间：
2002-01-22
期刊：
影响因子：
2.9
通讯作者：
Kuznetsova, IM
中科院分区：
文献类型：
--
作者：
Turoverov, KK;Verkhusha, VV;Kuznetsova, IM
研究了盐酸胍诱导的肌动蛋白去折叠的动力学。在获得的实验数据的基础上，提出了肌动蛋白展开的新动力学途径。我们已经证明，盐酸胍 (GdnHCl) 诱导的从天然肌动蛋白到失活肌动蛋白的转变经历了蛋白质的基本解折叠。这意味着失活的肌动蛋白应被视为非途径物种，而不是肌动蛋白的天然状态和完全展开状态之间的中间构象，正如之前所假设的那样。确定了产生失活肌动蛋白的转变的速率常数。在 1.0-2.0 M GdnHCl 下，从天然肌动蛋白到基本未折叠肌动蛋白转变的速率常数值超过了后续失活肌动蛋白形成步骤的速率常数值。它导致本质上未折叠的大分子在未折叠过程的早期积累，进而导致色氨酸荧光强度、表征固有荧光光谱位置的参数A和色氨酸荧光各向异性的时间依赖性最小。
The kinetics of actin unfolding induced by guanidine hydrochloride has been studied. On the basis of obtained experimental data a new kinetic pathway of actin unfolding was proposed. We have shown that the transition from native to inactivated actin induced by guanidine hydrochloride (GdnHCl) passes through essential unfolding of the protein. This means that inactivated actin should be considered as the off-pathway species rather than an intermediate conformation between native and completely unfolded states of actin, as has been assumed earlier. The rate constants of the transitions that give rise to the inactivated actin were determined. At 1.0-2.0 M GdnHCl the value of the rate constant of the transition from native to essentially unfolded actin exceeds that of the following step of inactivated actin formation. It leads to the accumulation of essentially unfolded macromolecules early in the unfolding process, which in turn causes the minimum in the time dependencies of tryptophan fluorescence intensity, parameter A, characterizing the intrinsic fluorescence spectrum position, and tryptophan fluorescence anisotropy.