title: Reverse pH-dependence of chromophore protonation explains the large Stokes shift of the red fluorescent protein mKeima.
abstract: The recently developed red fluorescent protein Keima exhibits the largest Stokes shift (180 nm) observed to date. Combining X-ray crystallography with (in crystallo) UV-visible absorption, fluorescence, and Raman spectroscopy, we have investigated molecular determinants of this peculiar property. The results demonstrate a pH-dependent "reverse chromophore protonation" triggered by the key residue Asp157 and which couples to cis/trans isomerization of the chromophore. These data provided guidelines to rationally design a useful Keima variant.
authors.affiliation: Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire de Physiologie Cellulaire Végétale, CEA, CNRS, INRA, Université Joseph Fourier, 17 rue des Martyrs, F-38054 Grenoble, France.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Violot
authors.forename: Philippe
authors.initials: P
authors.lastname: Carpentier
authors.forename: Laurent
authors.initials: L
authors.lastname: Blanchoin
authors.forename: Dominique
authors.initials: D
authors.lastname: Bourgeois
mesh_terms: D000042:Absorption; D018360:Crystallography, X-Ray; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D008164:Luminescent Proteins / Q000737:chemistry*; D011522:Protons; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D013237:Stereoisomerism; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D011522:Protons; D000097573:Red Fluorescent Protein