Physik Department E22, Technische Universität München, James Franck Strasse, 85748 Garching, Germany.
Proc Natl Acad Sci U S A. 2010 Feb 2;107(5):2013-8. doi: 10.1073/pnas.0909854107. Epub 2010 Jan 19.
Kinetic bulk and single molecule folding experiments characterize barrier properties but the shape of folding landscapes between barrier top and native state is difficult to access. Here, we directly extract the full free energy landscape of a single molecule of the GCN4 leucine zipper using dual beam optical tweezers. To this end, we use deconvolution force spectroscopy to follow an individual molecule's trajectory with high temporal and spatial resolution. We find a heterogeneous energy landscape of the GCN4 leucine zipper domain. The energy profile is divided into two stable C-terminal heptad repeats and two less stable repeats at the N-terminus. Energies and transition barrier positions were confirmed by single molecule kinetic analysis. We anticipate that deconvolution sampling is a powerful tool for the model-free investigation of protein energy landscapes.
动力学批量和单分子折叠实验可以描述势垒特性，但很难获得势垒顶部和天然状态之间折叠景观的形状。在这里，我们使用双光束光学镊子直接提取单个 GCN4 亮氨酸拉链分子的完整自由能景观。为此，我们使用解卷积力谱法以高时间和空间分辨率跟踪单个分子的轨迹。我们发现 GCN4 亮氨酸拉链结构域的异质能量景观。能量分布分为两个稳定的 C 端七肽重复和两个在 N 端不太稳定的重复。通过单分子动力学分析证实了能量和转换势垒位置。我们预计，解卷积采样是无模型研究蛋白质能量景观的有力工具。
