Rational Design of a Two‐Photon Fluorescent Probe for Human Cytochrome P450 3A and the Visualization of Mechanism‐Based Inactivation

Abstract Mechanism‐based inactivation (MBI) can mediate adverse reactions and hepatotoxicity from drugs, which is a result of their conversion into highly reactive metabolites catalyzed by enzymes such as cytochrome P450 3A (CYP3A). In the present research, we optimized the key interaction domain of the fluorophore with the target protein to develop a two‐photon fluorescent probe for CYP3A that is involved in the metabolism of more than half of all clinical drugs. The developed BN‐1 probe exhibited appropriate selectivity and sensitivity for the semi‐quantitative detection and imaging of endogenous CYP3A activity in various living systems, thereby providing a high‐throughput screening system enabling evaluation of MBI‐associated hepatotoxicity by CYP3A. Using BN‐1 as a fluorescent molecular tool facilitates the efficient discovery and characterization of CYP3A‐induced MBI in natural systems.