Scheme 4

Passerini bioconjugation for the assembly of multivalent glycoconjugates incorporating bacterial polysaccharide antigens. A Repeating unit of the pneumococcal serotype 14 (Pn14) and the meningococcal serogroup C (MenC) capsular polysaccharides (CPs). B SE-HPLC traces (TSK 5000 PW column) of the natural, fragmented and—for CPs Pn14—oxidized polysaccharides. C Schematic representation of the structures of the multivalent BSA-MenC-Pn14 glycoconjugates produced by the Passerini bioconjugation with isocyanoproteins. D Antigenicity evaluation by Dot blot assays of glycoconjugates 23, 24, 25 and 26 in comparison with isocyano-BSAs and modified CPs, using reference antibodies against BSA, S. pneumoniae and N. meningitidis. Native BSA and the natural CPs antigens were used as positive controls.