Microsecond protein dynamics observed at the single-molecule level

Microsecond protein dynamics observed at the single-molecule level

How polypeptide chains acquire specific conformations to realize unique biological functions is a central problem of protein science. Single-molecule spectroscopy, combined with fluorescence resonance energy transfer, is utilized to study the conformational heterogeneity and the state-to-state transition dynamics of proteins on the submillisecond to second timescales. However, observation of th...

Visualizing protein-DNA interactions at the single-molecule level.

Recent advancements in single-molecule methods have allowed researchers to directly observe proteins acting on their DNA targets in real-time. Single-molecule imaging of protein-DNA interactions permits detection of the dynamic behavior of individual complexes that otherwise would be obscured in ensemble experiments. The kinetics of these processes can be monitored directly, permitting identifi...

Microsecond dynamics of an unfolded protein by a line confocal tracking of single molecule fluorescence

We present a new method for high speed tracking of fluorescence time series from single proteins. The method uses a fast sample flow and a modified confocal microscopy, line confocal microscopy, and achieves the time resolution of less than 20 μs. The obtained time series from the B domain of protein A labeled with donor and acceptor fluorophores suggest conformational heterogeneity and dynamic...

Single Molecule Dynamics at Surfaces

Mass action at the single-molecule level.

We developed a system to reversibly encapsulate small numbers of molecules in an array of nanofabricated "dimples". This system enables highly parallel, long-term, and attachment-free studies of molecular dynamics via single-molecule fluorescence. In studies of bimolecular reactions of small numbers of confined molecules, we see phenomena that, while expected from basic statistical mechanics, a...