The Gram-negative encapsulated bacterium Neisseria meningitidis type A (MenA) is a major cause of meningitis in developing countries, especially in the sub-Saharan region of Africa. The development and manufacture of an efficient glycoconjugate vaccine against MenA is greatly hampered by the poor hydrolytic stability of its capsular polysaccharide, consisting of (1→6)-linked 2-acetamido-2-deoxy--D-mannopyranosyl phosphate repeating units. The replacement of the ring oxygen with a methylene group to get a carbocyclic analogue leads to the loss of the acetalic character of the phosphodiester and consequently to the enhancement of its chemical stability. Here we report the synthesis of oligomers (mono-, di- and trisaccharide) of carba-N-acetylmannosamine-1-O-phosphate as candidates for stabilized analogues of the corresponding fragments of MenA capsular polysaccharide. Each of the synthesized compounds contains a phosphodiester-linked aminopropyl spacer at its reducing end to allow for protein conjugation. The inhibition abilities of the synthetic molecules were investigated by a competitive ELISA assay, showing that only the carba-disaccharide is recognized by a polyclonal anti-MenA serum with an affinity similar to a native MenA oligosaccharide with average polymerization degree 3.
Synthesis and Preliminary Biological Evaluation of Carba Analogues from Neisseria meningitidis A Capsular Polysaccharide / Q. Gao, C. Zaccaria, M. Tontini, L. Poletti, P. Costantino, L. Lay. - In: ORGANIC & BIOMOLECULAR CHEMISTRY. - ISSN 1477-0520. - 10:33(2012), pp. 6673-6681.
Titolo: | Synthesis and Preliminary Biological Evaluation of Carba Analogues from Neisseria meningitidis A Capsular Polysaccharide | |
Autori: | GAO, QI (Primo) ZACCARIA, CRISTINA (Secondo) LAY, LUIGI (Ultimo) | |
Parole Chiave: | PROTEIN CONJUGATE VACCINES ; GROUP-A ; GOLD NANOPARTICLES ; ANTIGENS ; PREVENTION; PROTECTION ; SEROGROUPS | |
Settore Scientifico Disciplinare: | Settore CHIM/06 - Chimica Organica | |
Data di pubblicazione: | 2012 | |
Rivista: | ||
Tipologia: | Article (author) | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1039/C2OB25222H | |
Appare nelle tipologie: | 01 - Articolo su periodico |