TY - JOUR
T1 - Selectively charged and zwitterionic analogues of the smallest immunogenic structure of Streptococcus pneumoniae type 14
AU - Gragnani, Tiziana
AU - Cuffaro, Doretta
AU - Fallarini, Silvia
AU - Lombardi, Grazia
AU - D’Andrea, Felicia
AU - Guazzelli, Lorenzo
N1 - Publisher Copyright:
© 2019 by the authors
PY - 2019/9/19
Y1 - 2019/9/19
N2 - Zwitterionic polysaccharides (ZPs) have been shown in recent years to display peculiar immunological properties, thus attracting the interest of the carbohydrate research community. To fully elucidate the mechanisms underlying these properties and exploit the potential of this kind of structures, in depth studies are still required. In this context, the preparation of two cationic, an anionic, as well as two zwitterionic tetrasaccharide analogues of the smallest immunogenic structure of Streptococcus pneumoniae type 14 (SP14) capsular polysaccharide are presented. By exploiting a block strategy, the negative charge has been installed on the non-reducing end of the lactose unit of the tetrasaccharide and the positive charge either on the non-reducing end of the lactosamine moiety or on an external linker. These structures have then been tested by competitive ELISA, showing that the structural variations we made do not modify the affinity of the neutral compound to binding to a specific antibody. However, lower efficacies than the natural SP14 compound were observed. The results obtained, although promising, point to the need to further elongate the polysaccharide structure, which is likely too short to cover the entire epitopes.
AB - Zwitterionic polysaccharides (ZPs) have been shown in recent years to display peculiar immunological properties, thus attracting the interest of the carbohydrate research community. To fully elucidate the mechanisms underlying these properties and exploit the potential of this kind of structures, in depth studies are still required. In this context, the preparation of two cationic, an anionic, as well as two zwitterionic tetrasaccharide analogues of the smallest immunogenic structure of Streptococcus pneumoniae type 14 (SP14) capsular polysaccharide are presented. By exploiting a block strategy, the negative charge has been installed on the non-reducing end of the lactose unit of the tetrasaccharide and the positive charge either on the non-reducing end of the lactosamine moiety or on an external linker. These structures have then been tested by competitive ELISA, showing that the structural variations we made do not modify the affinity of the neutral compound to binding to a specific antibody. However, lower efficacies than the natural SP14 compound were observed. The results obtained, although promising, point to the need to further elongate the polysaccharide structure, which is likely too short to cover the entire epitopes.
KW - Competitive ELISA
KW - Streptococcus pneumoniae type 14
KW - Zwitterionic analogues
UR - http://www.scopus.com/inward/record.url?scp=85072578445&partnerID=8YFLogxK
U2 - 10.3390/molecules24183414
DO - 10.3390/molecules24183414
M3 - Article
SN - 1420-3049
VL - 24
JO - Molecules
JF - Molecules
IS - 18
M1 - 3414
ER -