Probing Single-Molecule Protein Spontaneous Folding–Unfolding
Conformational Fluctuation Dynamics: The Multiple-State and Multiple-Pathway
Energy Landscape
- Publication date
- 2015
- Publisher
Abstract
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