Fluorogenic substrates for lipases, esterases, and acylases using a TIM-mechanism for signal release

Area of Science:

• Enzyme kinetics and assay development
• Biochemistry and molecular biology
• Fluorescent probe design

Background:

• Lipases and esterases are crucial enzymes involved in various biological and industrial processes.
• Developing sensitive and specific fluorogenic substrates is essential for enzyme activity monitoring.
• Existing substrates may have limitations, such as requiring specific conditions or reagents.

Purpose of the Study:

• To synthesize and characterize novel fluorogenic substrates for lipases and esterases.
• To investigate the mechanism of fluorescence release.
• To establish these substrates as periodate-free alternatives for enzyme detection.

Main Methods:

• Synthesis of 3-acyloxyl-2-oxopropyl ethers of umbelliferone.
• Design and synthesis of a phenylacetamide-based probe.
• Enzyme assays using lipases, esterases, penicillin G acylase, and epoxide hydrolases.
• Spectrofluorometric analysis to monitor fluorescence emission.

Main Results:

• The umbelliferone derivatives acted as effective fluorogenic substrates for lipases and esterases.
• A rapid enolization/beta-elimination reaction released umbelliferone, enabling sensitive detection.
• A phenylacetamide probe was developed for penicillin G acylase, showing fast and spontaneous reaction.
• The corresponding epoxyketone was not fluorogenic with epoxide hydrolases.

Conclusions:

• 3-Acyloxyl-2-oxopropyl ethers of umbelliferone are efficient fluorogenic substrates for lipases and esterases.
• The developed substrates offer a periodate-free approach for enzyme activity measurement.
• These novel probes demonstrate potential for sensitive and specific enzyme detection in various applications.