Ultrafast fluorescence depolarisation in the yellow fluorescent protein due to its dimerisation. |
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Authors: | Gregor Jung Yingzhong Ma Bradley S Prall Graham R Fleming |
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Institution: | Department of Chemistry, University of California, Berkeley and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-1460, USA. g.jung@mx.uni-saarland.de |
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Abstract: | Transient absorption spectroscopy with sub-100 fs time resolution was performed to investigate the oligomerisation behaviour of eYFP in solution. A single time constant tau(AD)=2.2+/-0.15 ps is sufficient to describe the time-resolved anisotropy decay up to at least 200 ps. The close contact of two protein barrels is deduced as the exclusive aggregation state in solution. From the final anisotropy r(infinity)=0.28+/-0.02, the underlying quaternary structure can be traced back to the somewhat distorted structure of the dimers of wt-GFP. The use of autofluorescent proteins as rulers in F?rster resonance energy transfer (FRET) measurements may demand polarisation-sensitive detection of the fluorescence with high time resolution. |
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Keywords: | fluorescence FRET (fluorescence resonance energy transfer) proteins single‐molecule studies time‐resolved spectroscopy |
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