An enzyme-linked lectin assay for sialidase

Area of Science:

• Biochemistry
• Enzymology
• Molecular Biology

Background:

• Sialidases (neuraminidases) are enzymes that cleave sialic acids.
• Detection of low sialidase activity is crucial for various biological and clinical applications.
• Existing methods may lack sensitivity or require complex procedures.

Purpose of the Study:

• To develop a sensitive and reliable assay for detecting low sialidase activity.
• To utilize peanut agglutinin lectin (PNA) for quantifying enzyme-mediated substrate desialylation.
• To establish a method applicable to various biological sources, including bacteria, viruses, and mammalian cells.

Main Methods:

• Coating microplate wells with natural sialidase substrates (erythrocytes, fetuin, gangliosides).
• Incubation with enzyme samples at 37°C to allow desialylation.
• Detection of unmasked saccharides using peroxidase-conjugated peanut agglutinin lectin (Po-PNA).
• Quantification of Po-PNA binding via spectrophotometry, correlating with sialidase activity.

Main Results:

• The assay demonstrated a direct correlation between bound Po-PNA and released sialic acid, indicating sialidase activity.
• The method successfully detected sialidase activity in bacterial, myxoviral, and mammalian cell preparations.
• Sensitivity allows for the detection of low enzyme activities.

Conclusions:

• A novel, sensitive enzyme-linked immunosorbent assay (ELISA) for sialidase activity detection has been established.
• The assay leverages PNA's specific binding to desialylated substrates for quantification.
• This method holds potential for automated, high-throughput analysis with significant clinical implications.