Before revision:  Here we show a novel plasmon ruler based single molecule approach to study the conformational dynamics of single proteins over 24 hours at video rate in and out of equilibrium (i. e. in the absence and presence of ATP). This approach does not impose external force on the proteins and allows to measure protein dynamics over several orders of magnitude, which cannot be achieved by the established single molecule techniques. We used this technique to explore the dynamics of the  heat shock protein 90 (Hsp90) and find (beside the well-known fast dynamics in the range netween 0.1 and 10 s) states with very long dwell times (linked to rarely visited states) in the minute timescale, which could indicate, for instance, pathways to protein denaturation.
After revision:  Here we show a novel plasmon ruler based single molecule approach to study the conformational dynamics of single proteins over 24 h at a video rate. The plasmon ruler consists of two gold nanospheres connected by a single protein linker. In our experiment, we follow the dynamics of the heat shock protein 90 (Hsp90) and find (beside the well-known fast dynamics in the range netween 0.1 and 10 s) states with very long dwell times (linked to rarely visited states) in the minute timescale, which could indicate, for instance, pathways to protein denaturation.