Characterization of Borrelia burgdorferi glycoconjugates and surface carbohydrates.

Borrelia burgdorferi glycoconjugates with different oligosaccharide structures were characterized by a blotting technique with peroxidase-labelled lectins. The localization of surface carbohydrates was studied using electron microscopy with lectin-gold complexes. A high-mannose glycan structure was detected in 83 kDa glycoprotein (major extracellular protein); at least four carbohydrates (glucose or mannose, galactose, N-acetylgalactosamine and N-acetylglucosamine) were present in other Borrelia glycoconjugates. N-acetylneuraminic (sialic) acid was detected on the Borrelia surface. Two sialidases with different specificities were used in an attempt to cleave off the Borrelia N-acetylneuraminic acid. The attempt was successful by using Vibrio cholerae sialidase which has a broad substrate specificity, while the mumps-virus sialidase with restricted substrate specificity had no effect. Endogenous activity of N-acetylneuraminidase was not demonstrated in B. burgdorferi K 5 and B 31 strains.