Rational Design of a Long-Wavelength Fluorescent Probe for Highly Selective Sensing of Carboxylesterase 1 in Living Systems

Abstract

Rational design of practical probes with excellent specificity and improved optical properties for a particular enzyme is always a big challenge. Herein, a practical and highly specific fluorescent probe for carboxylesterase 1 (CES1) was rationally designed using meso-carboxyl-BODIPY as the basic fluorophore based on the substrate preference and catalytic properties of CES1. Following molecular docking-based virtual screening combined with reaction phenotyping-based experimental screening, we found that MMB (probe 7) exhibited the optimal combination of sensitivity and specificity toward human CES1 in contrast to other ester derivatives. Under physiological conditions, MMB could be readily hydrolyzed by CES1 and release MCB; such biotransformation brought great changes in the electronic properties at the meso position of the fluorophore and triggered a dramatic increase in fluorescence emission around 595 nm. Moreover, MMB was cell membrane permeable and was successfully applied to monitor the real activities of CES1 in various biological samples including living cells, tissue slices, organs, and zebrafish. In summary, this study showed a good example for constructing specific fluorescent probe(s) for a target enzyme and also provided a practical and sensitive tool for real-time sensing of CES1 activities in complicated biological samples. All these findings would strongly facilitate high-throughput screening of CES1 modulators and the studies on CES1-associated physiological and pathological processes.

Advances in Activity‐Based Sensing Probes for Isoform‐Selective Imaging of Enzymatic Activity

“…The authors identified the lead compound MMB, which contains a methyl ester and dichloro‐functionalization of the BODIPY (Figure 3 e). MMB was applied for live‐cell imaging, ex vivo tissue analysis of CE1 activity (tissue slices and whole organ), and live animal imaging in zebrafish [36] . Altogether, these studies highlight the utility of searching the literature for existing substrates/inhibitors and employing molecular docking to design isoform‐selective ABS probes.…”

A Minireview of Recent Reported Carboxylesterase Fluorescent Probes: Design and Biological Applications

“…Cui et al. developed a long‐wavelength fluorescent probe 12 which can sensitively monitor carboxylesterase 1 (CES1) utilizing meso‐carboxyl‐BODIPY as the fluorophore (Figure b) . BODIPY derivatives have excellent photostabilities, and can modulate photophysical properties easily with proper substitution .…”

Chemically modified nucleic acid biopolymers used in biosensing

“…Recently, much work has integrated biological functions into biosensing to achieve biomedical functions with high sensitivity and specificity. [90][91][92] This requires that the materials used in biosensing can interact with and respond to target signals uniquely. Nucleic acid biopolymers show recognition ability to target molecules with good selectivity.…”