Publication Date:
2013-04-04
Description:
Fluorescent proteins undergoing green to red (G/R) photoconversion have proved to be potential tools for investigating dynamic processes in living cells and for photo-localization nanoscopy. However, the photochemical reaction during light induced G/R photoconversion of fluorescent proteins remains unclear. Here we report the direct observation of ultrafast time-resolved electron transfer (ET) during the photoexcitation of the fluorescent proteins EGFP and mEos2 in presence of electron acceptor, p-benzoquinone (BQ). Our results show that in the excited state, the neutral EGFP chromophore accepts electrons from an anionic electron donor, Glu222, and G/R photoconversion is facilitated by ET to nearby electron acceptors. By contrast, mEos2 fails to produce the red emitting state in the presence of BQ; ET depletes the excited state configuration en route to the red-emitting fluorophore. These results show that ultrafast ET plays a pivotal role in multiple photoconversion mechanisms and provide a method to modulate the G/R photoconversion process. Scientific Reports 3 doi: 10.1038/srep01580
Electronic ISSN:
2045-2322
Topics:
Natural Sciences in General
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