Regensburg 2016 – scientific programme

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BP: Fachverband Biologische Physik

BP 11: Bioimaging and Spectroscopy II

BP 11.4: Invited Talk

Monday, March 7, 2016, 16:00–16:30, H43

Chromophore Photophysics in Fluorescent Proteins of the GFP family — •Gerd Ulrich Nienhaus — Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany — Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany — Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany — Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA

Genetically encoded fluorescent proteins (FPs) of the green fluorescent protein (GFP) family have become indispensable as marker tools for imaging live cells, tissues and entire organisms. Great efforts are ongoing in many labs to further optimize their photophysical properties by genetic engineering. The p-HBI chromophore of GFP (or a variant thereof in other FPs), which forms autocatalytically in the interior of the polypeptide chain, is exquisitely sensitive to the protein environment. By introducing amino acid modifications, its photophysical properties can be changed, e.g., for the purpose of color tuning. In photoactivatable FPs, chromophore properties can even be controlled by light irradiation, which is of key relevance for super-resolution optical imaging. Photoactivation may occur reversibly, by photoinduced cis-trans isomerization of the chromophore (photoswitching), or by permanent photochemical modifications (photoconversion). Here I shall discuss these photophysical effects in the context of the underlying mechanisms.