A microtiter plate assay for N-acetyl-beta-D-glucosaminidase using a fluorogenic substrate.

Area of Science:

• Biochemistry
• Enzyme Assays
• Biotechnology

Background:

• N-acetyl-beta-D-glucosaminidase (NAGase) is an enzyme with diagnostic relevance.
• Existing methods for NAGase determination may lack speed or high throughput.
• Accurate and efficient NAGase measurement is crucial for diagnosing conditions like bovine mastitis.

Purpose of the Study:

• To develop and validate a simple, rapid, and reproducible endpoint method for quantifying N-acetyl-beta-D-glucosaminidase (NAGase) activity.
• To assess the suitability of the developed assay for high-throughput screening of biological samples.
• To explore the application of the NAGase assay in veterinary diagnostics, specifically for bovine subclinical mastitis.

Main Methods:

• Utilized a fluorogenic substrate, 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide, for NAGase activity determination.
• Performed assays at pH 4.6, measuring the liberated fluorescent product, 4-methylumbelliferone.
• Optimized the procedure for both room temperature and 37 degrees C incubation, employing 96-well microtiter plates and automated fluorescence readers for high-throughput analysis.

Main Results:

• The developed endpoint method for NAGase determination is reproducible and rapid.
• The assay demonstrates high capacity and sensitivity, enabling screening of hundreds of milk samples per hour.
• Elevated NAGase activities were observed in raw milk samples, consistent with bovine subclinical mastitis.

Conclusions:

• The described fluorogenic assay provides a simple, fast, and reproducible method for NAGase determination.
• The assay's high throughput and sensitivity make it suitable for large-scale screening, particularly in bovine mastitis diagnosis.
• This NAGase assay holds potential for diagnosing both veterinary and human diseases.