An Activatable Chemiluminescent Probe for Sensitive Detection of γ-Glutamyl Transpeptidase Activity in Vivo

Abstract

Activatable chemiluminescent probes that show enhanced chemiluminescence upon interaction with a molecular target of interest have offered promising tools for sensing and bioimaging in terms of low background, high sensitivity, and improved penetration depth in biological tissues. Here, we reported a γ-glutamyl transpeptidase (GGT) activatable chemiluminescent probe for real-time detection of GGT activity in vitro and in living mice. The probe was designed by caging an electron-withdrawing acrylic group-substituted Schaap’s phenoxy-dioxetane with a GGT-recognitive substrate (γ-Glu) and a self-immolative linker (p-aminobenzyl alcohol), which was initially chemiluminescence off. Upon interaction with GGT, strong chemiluminescence with a more than 800-fold turn-on ratio could be achieved in aqueous solution, allowing to specifically detect GGT activity with ultrahigh signal-to-background ratio and sensitivity in vitro and in live cells. We demonstrated that the probe was reliable to quantify the GGT in serum, permitting to accurately report the elevated levels of GGT in lipopolysaccharide-treated mouse serum. Moreover, through real-time chemiluminescence imaging of GGT activity, the designed probe was feasible to detect GGT-positive tumors in living mice after intravenous systemic administration. This study demonstrates the high potential of GGT-activatable chemiluminescent probe for serum assays and molecular imaging, which might find wide applications in diagnosis of GGT-related diseases.

Activatable Molecular Probes for Second Near‐Infrared Fluorescence, Chemiluminescence, and Photoacoustic Imaging

“…[48] Ye et al synthesized an activatable chemiluminescent probe for real-time detection of GGT activity in living mice. [49] Probe 1c omprised three key functional moieties:aGGTcleavable amino acid substrate g-Glu, aself-immolative linker PA BA,a nd ah ighly emissive acryl-substituted phenoxydioxetane luminophore (Figure 8a). Probe 1w as initially non-chemiluminescent.…”

Molecular Chemiluminescent Probes with a Very Long Near‐Infrared Emission Wavelength for in Vivo Imaging

“…Such a generic molecular design enables ultrasensitive chemiluminescence imaging of various enzymes (e.g. nitroreductase, [15] γ‐glutamyl transpeptidase, [16] cathepsins, [17] etc [18, 19] …”

Activatable Molecular Probes for Second Near‐Infrared Fluorescence, Chemiluminescence, and Photoacoustic Imaging

“…Ye et al. synthesized an activatable chemiluminescent probe for real‐time detection of GGT activity in living mice . Probe 1 comprised three key functional moieties: a GGT‐cleavable amino acid substrate γ‐Glu, a self‐immolative linker PABA, and a highly emissive acryl‐substituted phenoxy‐dioxetane luminophore (Figure a).…”