A fluorescence-based microtiter plate assay for γ-glutamylcyclotransferase

Area of Science:

• Biochemistry
• Enzymology
• Assay Development

Background:

• Gamma-glutamylcyclotransferase (GGCT) is crucial in the gamma-glutamyl cycle.
• GGCT activity leads to 5-oxoproline accumulation in glutathione synthetase deficiency.
• GGCT is implicated as a potential biomarker in various cancers.

Purpose of the Study:

• To develop a high-throughput screening assay for GGCT inhibitors.
• To facilitate the study of GGCT's role in disease and cancer.

Main Methods:

• A fluorescence-based 96-well plate assay was developed.
• Assay measures the rate of gamma-glutamylcysteine cleavage by GGCT.
• Residual substrate is quantified via fluorometric detection after derivatization.

Main Results:

• The assay demonstrates sensitivity for detecting low-affinity competitive inhibitors.
• The method is simple and suitable for microtiter plate formats.
• The assay is effective for high-throughput screening of GGCT inhibitors.

Conclusions:

• A novel, sensitive, and high-throughput compatible assay for GGCT activity has been established.
• This assay will aid in discovering GGCT inhibitors for therapeutic applications and cancer research.