Dynamics of equilibrium folding and unfolding transitions of titin immunoglobulin domain under constant forces.
Dynamics of equilibrium folding and unfolding transitions of titin immunoglobulin domain under constant forces.
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DOI：
10.1021/ja5119368
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发表时间：
2015-03-18
影响因子：
15
通讯作者：
Yan, Jie
中科院分区：
文献类型：
--
作者：
Chen, Hu;Yuan, Guohua;Winardhi, Ricksen S.;Yao, Mingxi;Popa, Ionel;Fernandez, Julio M.;Yan, Jie
承力蛋白的机械稳定性对其功能至关重要。然而，复杂蛋白质结构域的缓慢转变速率使得研究其平衡力依赖性结构转变变得具有挑战性。使用超稳定磁力镊子，我们报告了经典 titin I27 免疫球蛋白结构域的第一个平衡单分子力操纵研究。我们发现串联重复中的单个 I27 独立展开/折叠。我们获得了展开和折叠 I27 之间与力相关的自由能差，并确定了展开和折叠具有相同概率的临界力 (∼5.4 pN)。我们还根据展开的自由能成本的测量确定了展开/折叠转变的力相关自由能景观。除了深入了解肌联蛋白 I27 的力依赖性结构转变外，我们的结果还表明，肌联蛋白免疫球蛋白结构域的构象在低力、长时间的肌肉拉伸过程中可能会发生显着改变。
The mechanical stability of force-bearing proteins is crucial for their functions. However, slow transition rates of complex protein domains have made it challenging to investigate their equilibrium force-dependent structural transitions. Using ultra stable magnetic tweezers, we report the first equilibrium single-molecule force manipulation study of the classic titin I27 immunoglobulin domain. We found that individual I27 in a tandem repeat unfold/fold independently. We obtained the force-dependent free energy difference between unfolded and folded I27 and determined the critical force (∼5.4 pN) at which unfolding and folding have equal probability. We also determined the force-dependent free energy landscape of unfolding/folding transitions based on measurement of the free energy cost of unfolding. In addition to providing insights into the force-dependent structural transitions of titin I27, our results suggest that the conformations of titin immunoglobulin domains can be significantly altered during low force, long duration muscle stretching.
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影响因子：
64.5
作者：
Alegre-Cebollada J;Kosuri P;Giganti D;Eckels E;Rivas-Pardo JA;Hamdani N;Warren CM;Solaro RJ;Linke WA;Fernández JM
通讯作者：
Fernández JM
影响因子：
3.4
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通讯作者：
Marqusee, Susan
影响因子：
56.9
作者：
Fernandez, JM;Li, HB
通讯作者：
Li, HB
影响因子：
56.9
作者：
LABEIT, S;KOLMERER, B
通讯作者：
KOLMERER, B
影响因子：
8.6
作者：
Harris, Nolan C.;Song, Yang;Kiang, Ching-Hwa
通讯作者：
Kiang, Ching-Hwa