A semi-synthetic glycoconjugate antigen prepared by chemical glycosilation of pertussis toxin by a meningococcal group C oligosaccharide hapten.

The preparation of a hybrid molecule obtained by chemical glycosilation of pertussis toxin (PT) is reported, with the purpose of obtaining a semi-synthetic glycoprotein antigen with bivalent antigenicity. The chemical glycosilation was performed using an oligosaccharide hapten derived from the purified capsular polysaccharide of Neisseria meningitidis group C. The semi-synthetic molecule was investigated by chemico-physical and immunochemical analysis. The oligosaccharide haptens appeared exposed on the surface of the carrier protein PT, since the glycoprotein inhibited the immunoprecipitate between a specific polyclonal antiserum and the native bacterial capsular polysaccharide. By contrast, the main antigenic regions recognized in the native protein PT by specific polyclonal antibodies appeared lost after the coupling procedure involving PT as the carrier protein.