Real-Time Detection of Reduced Nitroreductase with a Reversible Fluorescent Probe.

ABSTRACT: Nitroreductase (NTR), a class of flavin-dependent redox enzymes, is a key biomarker for hypoxic tumors. Numerous fluorescent NTR probes have been developed to study hypoxia and associated tumors; however, they are reaction-based and provide only static information on the accumulated enzyme activity at a given time. Reversible binding probes are needed to monitor the enzyme level in real time. Here, the first reversible binding probe is presented that selectively detects the active, reduced form of NTR (red-NTR) with a fluorescence turn-on response. This probe, a benzocoumarin dye functionalized with a (nitrobenzyl)pyridinium moiety, is stabilized through hydrogen bonding between its nitro group and the reduced cofactor flavin mononucleotide (FMNH₂). This interaction suppresses b

SUBMITTER: Sarkar S 

PROVIDER: S-EPMC12622434 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature