Enzyme-Triggered Chromogenic and Fluorogenic Probes for Myrosinase Activity Detection

Area of Science:

• Biochemistry
• Plant Science
• Enzymology

Background:

• Myrosinase, a thioglucosidase enzyme, plays a vital role in plant defense mechanisms within Brassicales species.
• It catalyzes the hydrolysis of glucosinolates (GSLs) into bioactive isothiocyanates, compounds known for their chemopreventive health benefits.
• Accurate detection of myrosinase activity is essential for understanding and optimizing isothiocyanate production from GSLs.

Purpose of the Study:

• To develop novel molecular tools for the spectrophotometric detection of myrosinase activity.
• To synthesize and validate chromogenic and fluorogenic glucosinolate analogs for enzyme activity assays.

Main Methods:

• Design and synthesis of two novel GSL analogs: GSL p-nitrophenoxy (GSL-pNP) and GSL-4-methylumbelliferone (GSL-4MU).
• Spectrophotometric quantification of myrosinase activity using the synthesized chromogenic GSL-pNP.
• In vitro activity monitoring of myrosinase in complex plant matrices using the fluorogenic GSL-4MU.

Main Results:

• The chromogenic GSL-pNP allows for the direct UV-vis detection and quantification of isolated myrosinase activity.
• The fluorogenic GSL-4MU serves as a reliable tool for monitoring myrosinase activity in complex biological samples, such as plant seeds.
• Both synthesized GSLs provide simple and effective methods for assessing myrosinase enzymatic function.

Conclusions:

• The developed chromogenic and fluorogenic GSL substrates are effective molecular tools for detecting and quantifying myrosinase activity.
• These tools facilitate the study of myrosinase function in both purified enzyme preparations and complex plant extracts.
• This research aids in the quality control and production of isothiocyanates from glucosinolates in dietary Brassicales plants.