In situ target enzyme-activated near-infrared fluorescent probe: A case study of CYP2J2 using three-fragmentary molecular assembly engineering

Cytochrome P450 2J2 (CYP2J2) is overexpressed in human carcinoma cells lines and malignant tumors, and has been closely related to the pathogenesis of cancers and further deterioration of the tumor. However, the molecular tools used for In Situ monitoring CYP2J2 are still rarely reported due to the multiplex of CYP2J2 enzyme structure and biological sample. Herein, a near-infrared (NIR) fluorescent probe (DPBM) with large Stokes shift (118 nm) for detection CYP2J2 was developed based on three-fragmentary molecular assembly engineering. The DPBM exhibited excellent specificity, high sensitivity and rapid 'turn-on' NIR emission for CYP2J2 relative to other CYP isoforms in the simulated physiological environment. The limit of detection of DPBM was calculated to be 0.09 nM for CYP2J2, insinuating that DPBM would be sensitive enough to perceive endogenous CYP2J2 activity. Indeed, the DPBM was successfully applied for real-time and long-term monitoring and bio-imaging of CYP2J2 activity in human liver microsomes (HLMs), living cells, isolated organs and In Situ tumor-bearing BALB/c nude mice. These findings insinuate that DPBM can accurately sense CYP2J2 enzyme activity in vitro/vivo, which maybe facilitate further explorations of physiological and pathological processes of CYP2J2-associated diseases.