Protein labeling using fluorogenic probes enables the facile visualization of proteins of interest. Herein, we report new fluorogenic probes consisting of a rationally designed coumarin ligand for the live-cell fluorogenic labeling of the photoactive yellow protein (PYP)-tag. On the basis of the photochemical mechanisms of coumarin and the probe-tag interactions, we introduced a hydroxy group into
NEAR INFRARED FLUOROGEN AND FLUORESCENT ACTIVATING PROTEINS FOR IN VIVO IMAGING AND LIVE-CELL BIOSENSING
申请人:Carnegie Mellon University
公开号:US20140243509A1
公开(公告)日:2014-08-28
Tissue slices and whole organisms offer substantial challenges to fluorescence imaging. Autofluorescence and absorption via intrinsic chromophores, such as flavins, melanin, and hemoglobins, confound and degrade output from all fluorescent tags. An “optical window,” farther red than most autofluorescence sources and in a region of low hemoglobin and water absorbance, lies between 650 and 900 nm. This valley of relative optical clarity is an attractive target for fluorescence-based studies within tissues, intact organs, and living organisms. Novel fluorescent tags were developed herein, based upon a genetically targeted fluorogen activating protein and cognate fluorogenic dye that yields emission with a peak at 733 nm exclusively when complexed as a “fluoromodule”. This tool improves substantially over previously described far-red/NIR fluorescent proteins in terms of brightness, wavelength, and flexibility by leveraging the flexibility of synthetic chemistry to produce novel chromophores.