Premium
Structural basis for the phototoxicity of the fluorescent protein KillerRed
Author(s) -
Carpentier Philippe,
Violot Sebastien,
Blanchoin Laurent,
Bourgeois Dominique
Publication year - 2009
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2009.07.041
Subject(s) - chromophore , phototoxicity , green fluorescent protein , reactive oxygen species , fluorescence , fluorescent protein , chemistry , photochemistry , cytotoxicity , biophysics , biochemistry , biology , physics , quantum mechanics , in vitro , gene
The red fluorescent protein KillerRed, engineered from the hydrozoan chromoprotein anm2CP, has been reported to induce strong cytotoxicity through the chromophore assisted light inactivation (CALI) effect. Here, we present the X‐ray structures of KillerRed in its native and bleached states. A long water‐filled channel is revealed, connecting the methylene bridge of the chromophore to the solvent. This channel facilitates the transit of oxygen and of reactive oxygen species (ROS) formed by reaction with the excited chromophore. The functional roles of key mutations used to produce KillerRed are discussed, strong chromophore distortions in the bleached state are revealed, and mechanisms for ROS production and self protection are proposed. The presence of a partially mature, photo‐resistant, green‐emitting state is characterized, which accounts for enhanced CALI by “pre‐bleached” KillerRed.