Molecular Basis of Spectral Diversity in Near-Infrared Phytochrome-Based Fluorescent Proteins.

摘要: Near-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes (BphPs) are the probes of choice for deep-tissue imaging. Detection several processes requires spectrally distinct NIR FPs. We developed an FP, BphP1-FP, which has most blue-shifted spectra and highest fluorescence quantum yield among BphP-derived found that these properties result binding biliverdin chromophore to a cysteine residue in GAF domain, unlike natural BphPs other BphP-based To elucidate molecular basis spectral shift, we applied biochemical, structural mass spectrometry analyses revealed formation unique species. Mutagenesis FPs different origins indicated mechanism shift is general can be used design multicolor BphPs. pairs point mutants cell labeling demonstrated they perform well model