|Title||Light driven ultrafast electron transfer in oxidative redding of Green Fluorescent Proteins. [Protein Technology Facility]|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Saha R, Verma PKumar, Rakshit S, Saha S, Mayor S, Pal SKumar|
|Keywords||Benzoquinones, Electron Transport, Green Fluorescent Proteins, Light, Oxidation-Reduction|
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.
|Alternate Journal||Sci Rep|
|PubMed Central ID||PMC3615570|