Structure of the L1 and L6 core oligosaccharide epitopes of Neisseriameningitidis

Abstract

. Can. J. Chem. 68, 1029 (1990). The core oligosaccharides obtained from the lipopolysaccharides of Neisseria menirlgitidis serotypes 1 and 6 were isolated by mild acid hydrolysis, and their structures elucidated by combined chemical, biochemical, and physical techniques. Use was made of 500 MHz 'H nuclear magnetic resonance measurements in both one-dimensional and two-dimensional modes as well as of nuclear Overhauser enhancement experiments. To assist in the structural assignments, the purified oligosaccharides were also degraded by chemical and enzymatic procedures to smaller fragments. The L1 oligosaccharide is a biantennary partially 0-acetylated heptasaccharide in which the larger antenna terminates in a a-D-Galp 1+4P-~-Galp l+4P-~-Glcp unit, whereas the smallest disaccharide antenna carries phosphorylethanolamine groups at 0 -3 of its heptosyl moiety. The L6 oligosaccharide is also a biantennary partially 0-acetylated heptasaccharide but, unlike the L1 core, is terminated by a P -D -G~c~N A c~+~P -DGalp I+4P-~-Glcp unit in its larger antenna. The heptosyl moiety in the small disaccharide antenna bears a phosphorylethanolamine group at 0-7, unlike 0 -3 for the L1 determinant.Key words: lipopolysaccharides, Neisseria meningitidis, oligosaccharide epitopes, structure, NMR spectroscopy. On a procCdC a une hydrolyse douce en milieu acide pour isoler les oligosaccharides de base des lipopolysaccharides du Neisseria meningitidis des strotypes 1 et 6; on a aussi ClucidC leurs structures en combinant des techniques chimiques, biochimiques et physiques. On a utilisC la rksonance magnCtique nucltaire du 'H dans les modes mono-et bi-dimensionnels ainsi que des expkriences d'effet Overhauser nuclCaire. Afin de faciliter les attributions de structure, on a aussi utilist des mCthodes chimiques ainsi qu'enzymatiques pour dkgrader les oligosaccharides en fragments plus petits. L'oligosaccharide L1, un heptasaccharide partiellement 0-acCtylC, portant deux antennes, dans lequel l'antenne la plus importante est une unit6 a -~-G a l p l + 4 P -~-G a l p l + 4 P -~-G l c p alors que la plus petite antenne est un disaccharide portant des groupements phosphorylCthanolamine en position 0 -3 de sa portion heptosyle. L'oligosaccharide L6 est aussi un heptasaccharide partiellement 0-acttylC portant deux antennes; toutefois, par opposition au produit L1, il se termine avec antenne portant une unit6 P-D-GlcpNAcl+3P-D-Galp 1+4P-~-Glcp. La portion heptosyle du disaccharide de la petite antenne porte un groupement phosphorylCthanolamine qui se trouve en position 0-7 plutdt qu'en 0 -3 comrne dans le dCterminant L1.

Human Lipooligosaccharide IGG That Prevents Endemic Meningococcal Disease Recognizes an Internal Lacto-N-neotetraose Structure

“…LOS synthesis by meningococci follows that by gonococci (45), except meningococci do not have an active LgtD. L3 and L7 strains substitute C 3 of Hep2 with PEA (16,18), catalyzed by Lpt3 (34), whereas L2, L4, and L6 strains substitute C 6 or C 7 of Hep2 with PEA (16,17,20), catalyzed by Lpt6 (35). L2 strains substitute C 3 of Hep2 with ␣-glucose (␣-Glc) (17), catalyzed by LgtG (33).…”

lpt6 , a Gene Required for Addition of Phosphoethanolamine to Inner-Core Lipopolysaccharide of Neisseria meningitidis and Haemophilus influenzae

“…4). PCR amplification was performed to determine if the genes lpt6 and lpt3 were present in the N. meningitidis LPS immunotyping reference L1 to L10 strains, for each of which the LPS structure has been characterized (11,13,22,29,35,36,49). The lpt6 gene was found in the L2, L4, L6, and L10 strains, and lpt3 was present in the L1, L3, L7, L8, and L9 strains.…”

Lipo-oligosaccharide immunotyping of Neisseria meningitidis by a whole-cell ELISA with monoclonal antibodies

“…16. The MAb against subtype P1.5 (Mn22A9.19) has been developed recently and was shown to be specific for the class 1 outer-membrane protein (OMP) by immunoblotting analysis.…”