摘要翻译：
单分子机械展开实验开始提供生物分子复杂能量景观的轮廓。为了获得能量景观特性的可靠估计，必须将实验测量与合理的理论模型和模拟相结合。在这里，我们展示了在激光光镊或AFM实验中，如何将温度作为生物分子机械展开的变量，可以在不对潜在反应坐标系做出任何假设的情况下测量能量景观的粗糙度。通过回顾直接测量蛋白质-蛋白质复合体粗糙度的实验结果，说明了该方法的有效性。粗糙度模型也可以用来解释温度变化时蛋白质的强迫去折叠实验。对能量景观的其他方面的估计，如自由能势垒或过渡态(TS)位置，可能取决于用于分析实验数据的精确模型。我们说明了从加载速率或与力相关的展开速率获得过渡态位置的内在困难。由于过渡态随力或加载速率的变化而移动，除非一维自由能曲线顶部的曲率较大，即势垒较尖锐，否则通常很难反演实验数据。TS位置对力的独立性只适用于脆性或坚硬的生物分子，而当分子是软的或塑性的时，TS位置变化很大。我们还评论了作为替代反应配位点的分子扩展的有用性，特别是在蛋白质和RNA的力猝灭复性的背景下。
---
英文标题：
《Measuring the energy landscape roughness and the transition state
  location of biomolecules using single molecule mechanical unfolding
  experiments》
---
作者：
Changbong Hyeon and D. Thirumalai
---
最新提交年份：
2006
---
分类信息：

一级分类：Physics        物理学
二级分类：Soft Condensed Matter        软凝聚态物质
分类描述：Membranes, polymers, liquid crystals, glasses, colloids, granular matter
膜，聚合物，液晶，玻璃，胶体，颗粒物质
--
一级分类：Physics        物理学
二级分类：Biological Physics        生物物理学
分类描述：Molecular biophysics, cellular biophysics, neurological biophysics, membrane biophysics, single-molecule biophysics, ecological biophysics, quantum phenomena in biological systems (quantum biophysics), theoretical biophysics, molecular dynamics/modeling and simulation, game theory, biomechanics, bioinformatics, microorganisms, virology, evolution, biophysical methods.
分子生物物理、细胞生物物理、神经生物物理、膜生物物理、单分子生物物理、生态生物物理、生物系统中的量子现象（量子生物物理）、理论生物物理、分子动力学/建模与模拟、博弈论、生物力学、生物信息学、微生物、病毒学、进化论、生物物理方法。
--
一级分类：Quantitative Biology        数量生物学
二级分类：Other Quantitative Biology        其他定量生物学
分类描述：Work in quantitative biology that does not fit into the other q-bio classifications
不适合其他q-bio分类的定量生物学工作
--

---
英文摘要：
  Single molecule mechanical unfolding experiments are beginning to provide profiles of the complex energy landscape of biomolecules. In order to obtain reliable estimates of the energy landscape characteristics it is necessary to combine the experimental measurements with sound theoretical models and simulations. Here, we show how by using temperature as a variable in mechanical unfolding of biomolecules in laser optical tweezer or AFM experiments the roughness of the energy landscape can be measured without making any assumptions about the underlying reaction oordinate. The efficacy of the formalism is illustrated by reviewing experimental results that have directly measured roughness in a protein-protein complex. The roughness model can also be used to interpret experiments on forced-unfolding of proteins in which temperature is varied. Estimates of other aspects of the energy landscape such as free energy barriers or the transition state (TS) locations could depend on the precise model used to analyze the experimental data. We illustrate the inherent difficulties in obtaining the transition state location from loading rate or force-dependent unfolding rates. Because the transition state moves as the force or the loading rate is varied it is in general difficult to invert the experimental data unless the curvature at the top of the one dimensional free energy profile is large, i.e the barrier is sharp. The independence of the TS location on force holds good only for brittle or hard biomolecules whereas the TS location changes considerably if the molecule is soft or plastic. We also comment on the usefulness of extension of the molecule as a surrogate reaction coordinate especially in the context of force-quench refolding of proteins and RNA.
---
PDF链接：
https://arxiv.org/pdf/cond-mat/0612433