Ultrafast fluorescence depolarisation in the yellow fluorescent protein due to its dimerisation.
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 Förster resonance energy transfer (FRET) measurements may demand polarisation-sensitive detection of the fluorescence with high time resolution.
Jung
Gregor
G
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
Ma
Yingzhong
Y
Prall
Bradley S
BS
Fleming
Graham R
GR
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D019281:Dimerization; D005454:Fluorescence Polarization; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D013997:Time Factors
D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria