Wang Zijian, Lu H Peter
Center for Photochemical Sciences, Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States.
J Phys Chem B. 2015 May 28;119(21):6366-78. doi: 10.1021/acs.jpcb.5b00735. Epub 2015 Apr 14.
Protein conformational dynamics often plays a critical role in protein functions. We have characterized the spontaneous folding-unfolding conformational fluctuation dynamics of calmodulin (CaM) at thermodynamic equilibrium conditions by using single-molecule fluorescence resonance energy transfer (FRET) spectroscopy. We have identified multiple folding transition pathways and characterized the underlying energy landscape of the single-molecule protein conformational fluctuation trajectories, using a model analysis based on the detailed balance rate process principle. Our results suggest that the folding dynamics of CaM molecules involves a complex multiple-pathway multiple-state energy landscape, rather than an energy landscape of two-state dynamical process. Our probing single-molecule FRET fluctuation experiments demonstrate a new approach of studying spontaneous protein folding-unfolding conformational dynamics at the equilibrium that features recording long time single-molecule conformational fluctuation trajectories.
蛋白质构象动力学在蛋白质功能中常常起着关键作用。我们利用单分子荧光共振能量转移（FRET）光谱，在热力学平衡条件下对钙调蛋白（CaM）的自发折叠-去折叠构象波动动力学进行了表征。我们基于细致平衡速率过程原理进行模型分析，确定了多条折叠转变途径，并对单分子蛋白质构象波动轨迹的潜在能量景观进行了表征。我们的结果表明，CaM分子的折叠动力学涉及复杂的多途径多状态能量景观，而非两态动力学过程的能量景观。我们的单分子FRET波动探测实验展示了一种在平衡状态下研究蛋白质自发折叠-去折叠构象动力学的新方法，其特点是记录长时间的单分子构象波动轨迹。
