A major Echinococcus multilocularis antigen is a mucin-type glycoprotein

Area of Science:

• Parasitology
• Glycobiology
• Biochemistry

Background:

• The metacestode of Echinococcus multilocularis features a carbohydrate-rich laminated layer essential for infection establishment.
• A key component of this layer is the Em2(G11) antigen, utilized in serodiagnosis for alveolar echinococcosis.

Purpose of the Study:

• To characterize the molecular structure of the Em2(G11) antigen.
• To elucidate the composition and sequence of its carbohydrate moieties.

Main Methods:

• Immunoaffinity purification and size-exclusion chromatography to assess molecular weight.
• Amino acid analysis to determine protein composition.
• Gas-chromatography/mass spectrometry and O-glycan profiling for carbohydrate analysis.

Main Results:

• Em2(G11) is a high molecular weight antigen, rich in threonine and proline.
• The carbohydrate moiety consists of galactose, N-acetylgalactosamine, and N-acetylglucosamine.
• Novel mucin-type core structures and branched glycoforms attached to serine and threonine residues were identified.

Conclusions:

• The Em2(G11) antigen is a mucin-type glycosylated protein.
• Detailed structural analysis provides insights into its role in Echinococcus multilocularis infection.