Development of a novel assay for proprotein converting enzyme activity on a multiplex bead-based array system.

Area of Science:

• Biochemistry
• Neuroscience
• Assay Development

Background:

• Proprotein converting enzymes are crucial for processing biologically active peptides.
• Dysregulation of proteolysis is implicated in various diseases, including neuropsychiatric disorders.
• Accurate measurement of enzyme activity is essential for understanding disease mechanisms.

Purpose of the Study:

• To develop a novel, robust assay system for measuring proprotein converting enzyme activity.
• To specifically develop and validate an assay for prolyl oligopeptidase (POP) activity.
• To investigate POP activity in postmortem pituitary extracts from schizophrenia patients.

Main Methods:

• A magnetic microsphere-based assay using a peptide-streptavidin substrate was developed.
• Prolyl oligopeptidase (POP) activity was detected by the loss of streptavidin signal on a MAGPIX reader.
• Assay results were validated using fluorometric and Western blot analyses.

Main Results:

• A novel and robust assay for POP activity was successfully developed.
• Increased POP activity was observed in postmortem pituitary extracts from schizophrenia patients compared to controls.
• Validation confirmed the reliability of the developed assay for POP activity measurement.

Conclusions:

• The novel assay system provides a robust method for determining proprotein converting enzyme activity.
• Elevated POP activity in schizophrenia suggests its potential involvement in the pathophysiology of the disease.
• The assay system is multiplexable and applicable to various clinical settings for studying diseases involving proteolysis.