NucPE1 (Nuclear Peroxy Emerald 1) is a nuclear-localized fluorescent hydrogen peroxide that is specifically localized to cellular nuclei without appended targeting moieties.
NucPE1 features two major visible region absorptions (λabs=468 nm, ε=27,300 M-1cm-1; λabs=490 nm, ε=26,000 M-1cm-1) and a weak emission (λem=530 nm, Φ=0.117). Reaction of NucPE1 with H2O2 triggers a fluorescence increase upon its conversion to fluorophore NucPE1, which possesses one major absorption band at 505 nm (ε=19,100 M-1cm-1) with enhanced emission (λem=530 nm, Φ=0.626). NucPE1 selectively accumulates in the nuclei of a variety of mammalian cell lines as well as in whole model organisms like C. clegans, where it can respond to subcellular changes in H2O2 fluxes[1].
NucPE1 maintains the ability to selectively target nuclei in vivo. NucPE1 imaging reveals a reduction in nuclear H2O2 levels in worms overexpressing sir-2.1 compared to wildtype congeners, supporting a link between this longevity-promoting sirtuin protein and enhanced regulation of nuclear ROS pools[1].
[1]. Stanicka J, et al. NADPH oxidase-generated hydrogen peroxide induces DNA damage in mutant FLT3-expressing leukemia cells. J Biol Chem. 2015 Apr 10;290(15):9348-61. [2]. Dickinson BC, et al. A nuclear-localized fluorescent hydrogen peroxide probe for monitoring sirtuin-mediated oxidative stress responses in vivo. Chem Biol. 2011 Aug 26;18(8):943-8.