Experimental free energy surface reconstruction from single-molecule force spectroscopy using Jarzynski's equality
Experimental free energy surface reconstruction from single-molecule force spectroscopy using Jarzynski's equality
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DOI：
10.1103/physrevlett.99.068101
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发表时间：
2007-08-10
影响因子：
8.6
通讯作者：
Kiang, Ching-Hwa
中科院分区：
文献类型：
--
作者：
Harris, Nolan C.;Song, Yang;Kiang, Ching-Hwa
我们使用原子力显微镜来操纵和展开肌联蛋白I27结构域的单个分子，并使用Jarzynski等式重建其自由能表面。拉伸和展开的自由能表面重建使用一个确切的公式，涉及到非平衡功波动的分子自由能。此外，展开的自由能垒，即，首次从实验数据中直接得到了反应的活化能。这封信表明，Jarzynski的平等可以用来分析非平衡单分子实验，并获得自由能表面的分子系统，包括相互作用，只有非平衡功可以测量。
We used the atomic force microscope to manipulate and unfold individual molecules of the titin I27 domain and reconstructed its free energy surface using Jarzynski's equality. The free energy surface for both stretching and unfolding was reconstructed using an exact formula that relates the nonequilibrium work fluctuations to the molecular free energy. In addition, the unfolding free energy barrier, i.e., the activation energy, was directly obtained from experimental data for the first time. This Letter demonstrates that Jarzynski's equality can be used to analyze nonequilibrium single-molecule experiments, and to obtain the free energy surfaces for molecular systems, including interactions for which only nonequilibrium work can be measured.