Shedding Light on the Dark and Weakly Fluorescent States of Green Fluorescent Proteins Export

@article{citeulike:2578279, abstract = {Recent experiments on various similar green fluorescent protein (GFP) mutants at the single-molecule level and in solution provide evidence of previously unknown short- and long-lived \"dark\" states and of related excited-state decay channels. Here, we present quantum chemical calculations on cis-trans photoisomerization paths of neutral, anionic, and zwitterionic GFP chromophores in their ground and first singlet excited states that explain the observed behaviors from a common perspective. The results suggest that favorable radiationless decay channels can exist for the different protonation states along these isomerizations, which apparently proceed via conical intersections. These channels are suggested to rationalize the observed dramatic reduction of fluorescence in solution. The observed single-molecule fast blinking is attributed to conversions between the fluorescent anionic and the dark zwitterionic forms whereas slow switching is attributed to conversions between the anionic and the neutral forms. The predicted nonadiabatic crossings are seen to rationalize the origins of a variety of experimental observations on a common basis and may have broad implications for photobiophysical mechanisms in GFP.}, author = {Weber, Wolfgang and Helms, Volkhard and Mccammon, Andrew J. and Langhoff, Peter W.}, citeulike-article-id = {2578279}, citeulike-linkout-0 = {http://www.jstor.org/stable/47844}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, keywords = {gfp}, number = {11}, pages = {6177--6182}, posted-at = {2008-03-24 04:31:09}, priority = {2}, title = {Shedding Light on the Dark and Weakly Fluorescent States of Green Fluorescent Proteins}, url = {http://www.jstor.org/stable/47844}, volume = {96}, year = {1999} }

TY - JOUR ID - citeulike:2578279 L3 - citeulike-article-id:2578279 N2 - Recent experiments on various similar green fluorescent protein (GFP) mutants at the single-molecule level and in solution provide evidence of previously unknown short- and long-lived "dark" states and of related excited-state decay channels. Here, we present quantum chemical calculations on cis-trans photoisomerization paths of neutral, anionic, and zwitterionic GFP chromophores in their ground and first singlet excited states that explain the observed behaviors from a common perspective. The results suggest that favorable radiationless decay channels can exist for the different protonation states along these isomerizations, which apparently proceed via conical intersections. These channels are suggested to rationalize the observed dramatic reduction of fluorescence in solution. The observed single-molecule fast blinking is attributed to conversions between the fluorescent anionic and the dark zwitterionic forms whereas slow switching is attributed to conversions between the anionic and the neutral forms. The predicted nonadiabatic crossings are seen to rationalize the origins of a variety of experimental observations on a common basis and may have broad implications for photobiophysical mechanisms in GFP. IS - 11 JF - Proceedings of the National Academy of Sciences of the United States of America EP - 6182 TI - Shedding Light on the Dark and Weakly Fluorescent States of Green Fluorescent Proteins VL - 96 SP - 6177 KW - gfp AU - Weber, Wolfgang AU - Helms, Volkhard AU - Mccammon, Andrew AU - Langhoff, Peter PY - 1999/// UR - http://www.jstor.org/stable/47844 ER -