@article {1010, title = {Light driven ultrafast electron transfer in oxidative redding of Green Fluorescent Proteins. [Protein Technology Facility]}, journal = {Sci Rep}, volume = {3}, year = {2013}, month = {2013}, pages = {1580}, abstract = {

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.

}, keywords = {Benzoquinones, Electron Transport, Green Fluorescent Proteins, Light, Oxidation-Reduction}, issn = {2045-2322}, doi = {10.1038/srep01580}, author = {Saha, Ranajay and Verma, Pramod Kumar and Rakshit, Surajit and Saha, Suvrajit and Mayor, Satyajit and Pal, Samir Kumar} }