Novel uses of fluorescent proteins

Abstract

The field of genetically encoded fluorescent probes is developing rapidly. New chromophore structures were characterized in proteins of green fluorescent protein (GFP) family. A number of red fluorescent sensors, for example, for pH, Ca(2+) and H2O2, were engineered for multiparameter imaging. Progress in development of microscopy hardware and software together with specially designed FPs pushed superresolution fluorescence microscopy towards fast live-cell imaging. Deeper understanding of FPs structure and photophysics led to further development of imaging techniques. In addition to commonly used GFP-like proteins, unrelated types of FPs on the base of flavin-binding domains, bilirubin-binding domains or biliverdin-binding domains were designed. Their distinct biochemical and photophysical properties opened previously unexplored niches of FP uses such as labeling under anaerobic conditions, deep tissue imaging and even patients' blood analysis.

Mechanism of resonant electron emission from the deprotonated GFP chromophore and its biomimetics

“…2,3 The molecular light machine at the heart of GFP is an extended π-system based on 4-hydroxybenzylidene-2,3-dimethylimidazolinone (HBDI) (Fig. 1) covalently bonded to the protein, which is wrapped around it with a β-barrel structure.…”

Crystal structure and fluorescence properties of the iSpinach aptamer in complex with DFHBI

“…The discovery of naturally fluorescent proteins had a profound impact on biology by making it possible to track proteins in the cell, but also monitoring gene expression as well as devising new innovative fluorogenic sensors (Enterina et al 2015;Mishin et al 2015). Even though no naturally fluorescent RNA has been discovered yet, several artificial fluorogenic RNAs have been developed.…”

Chemical reactivation of resin-embedded pHuji adds red for simultaneous two-color imaging with EGFP

“…The indirect precursor of pHuji, mOrange [23], has a chromophore surrounded by a stable β-barrel structure [24], which is similar to the β-barrel in GFP. Very likely pHuji also has such a structure, which may protect it from being damaged by resin embedding.…”