Detection of proteases using an immunochemical method with haptenylated-gelatin as a solid-phase substrate

Area of Science:

• Biochemistry
• Enzymology
• Immunochemistry

Background:

• Protease activity measurement is crucial in various scientific fields.
• Existing methods may lack sensitivity, specificity, or convenience.
• Solid-phase assays offer advantages in simplicity and reduced reagent consumption.

Purpose of the Study:

• To develop a simplified, sensitive, and broadly specific method for protease measurement.
• To utilize solid-phase substrates with ELISA for enzyme activity detection.
• To validate the method for quantifying bacterial protease activities.

Main Methods:

• A novel solid-phase immunochemical assay was developed using gelatin-hapten conjugates as substrates.
• Enzyme-linked immunosorbent assay (ELISA) with HRP-conjugated antibodies and a chromogenic substrate was employed for detection.
• The method was applied to quantify activities of bacterial proteases including alpha-chymotrypsin, and proteases from Bacillus polymyxa, Streptomyces griseus, and Bacillus licheniformens.

Main Results:

• The assay demonstrated a clear inverse relationship between the detectable signal and protease activity.
• Linear dose-response curves were established for various bacterial proteases within defined ranges.
• Low detection limits were achieved, with specific values reported for each protease studied.

Conclusions:

• The developed two-step immunochemical method provides a simple and sensitive approach for protease quantification.
• The use of gelatin as a substrate offers broad specificity for diverse proteases.
• This solid-phase format enhances assay flexibility and applicability in biochemical research.