Deeper insight into protease-sensitive "covalent-assembly" fluorescent probes for practical biosensing applications

Area of Science:

• Organic Chemistry
• Biochemistry
• Chemical Biology

Background:

• Novel protease-sensitive fluorescent probes were developed using a "covalent-assembly" strategy.
• Penicillin G acylase was employed as a model protease for constructing pyronin dyes via domino reactions.

Purpose of the Study:

• To structurally optimize fluorescent probes for enhanced performance in biological applications.
• To identify probe candidates with rapid "turn-on" fluorescence, stability in biological media, and payload release capabilities.

Main Methods:

• Screening of active methylene compounds (C-nucleophiles) to modify the parent probe.
• Synthesis of pyronin caged precursors with varying Michael acceptor reactivities.
• In vitro stability assays and fluorescent enzymatic assays with HPLC-fluorescence analysis.

Main Results:

• Identification of structural features crucial for fluorogenic scaffold performance.
• Demonstration of probe candidates suitable for biosensing and theranostics.
• Correlation between Michael acceptor reactivity and probe response.

Conclusions:

• Systematic structural optimization enables the development of advanced fluorescent probes.
• These probes show promise for applications in disease diagnosis and therapy.
• The study provides a framework for designing probes tailored to specific biological needs.