Protease and protease inhibitor assays using biotinylated casein coated on a solid phase

Area of Science:

• Biochemistry
• Enzymology
• Assay Development

Background:

• Proteases and protease inhibitors play critical roles in biological processes.
• Accurate quantification of enzyme activity is essential for research and diagnostics.
• Existing assay methods may lack sensitivity, simplicity, or automation capabilities.

Purpose of the Study:

• To develop a novel, sensitive, and automatable solid-phase assay for proteases and protease inhibitors.
• To utilize biotinylated casein as a substrate for enzyme activity detection.
• To establish a method for quantifying both protease activity and protease inhibitor levels.

Main Methods:

• Coating microtiter plate wells with biotinylated casein.
• Enzymatic hydrolysis of the substrate by proteases.
• Detection of unhydrolyzed substrate using an alkaline phosphatase-streptavidin complex.
• Quantification of bound alkaline phosphatase activity as an indicator of remaining casein.

Main Results:

• The assay demonstrates an inverse relationship between indicator enzyme activity and protease activity.
• The method is sensitive, accurate, and cost-effective.
• The assay is amenable to automation for high-throughput screening.

Conclusions:

• A robust solid-phase assay for proteases and protease inhibitors has been successfully developed.
• The assay offers a simple, sensitive, and automatable approach for enzyme activity measurement.
• This method has potential applications in biochemical research, drug discovery, and clinical diagnostics.