Watching conformational- and photodynamics of single fluorescent proteins in solution
|Title||Watching conformational- and photodynamics of single fluorescent proteins in solution|
|Publication Type||Journal Article|
|Year of Publication||2010|
|Authors||Goldsmith R.H, Moerner W.E|
|Keywords||allophycocyanin trimers, bile-pigments, brownian-motion, dynamics, energy-transfer, fluctuations, molecule fluorescence, photochemistry, spectroscopy, state relaxation|
Observing the dynamics of single biomolecules over prolonged time periods is difficult to achieve without significantly altering the molecule through immobilization. It can, however, be accomplished using the anti-Brownian electrokinetic trap, which allows extended investigation of solution-phase biomolecules-without immobilization-through real-time electrokinetic feedback. Here we apply the trap to study an important photosynthetic antenna protein, allophycocyanin. The technique allows the observation of single molecules of solution-phase allophycocyanin for more than one second. We observe a complex relationship between fluorescence intensity and lifetime that cannot be explained by simple static spontaneous emission lifetime, which is typically assumed to be constant. Our methods provide a new window into the dynamics of fluorescent proteins and the observations are relevant for the interpretation of in vivo single-molecule imaging experiments, bacterial photosynthetic regulation and biomaterials for solar energy harvesting.
|Alternate Journal||Nat Chem|