Conserved Structural Features of Core Oligosaccharides among the Lipopolysaccharides of Respiratory Pathogens from the Genus Analyzed Exclusively by NMR Spectroscopy.

Bacterial pathogens expose on the cell surface a variety of complex carbohydrate molecules. Gram-negative bacteria produce lipopolysaccharides, which are the main components of the outer membrane of bacterial envelopes and play a major role in host-pathogen interactions. , , and , are mammalian respiratory pathogens, having substantial economic impact on human health and agriculture. is responsible for whooping cough (pertussis) and is the second pertussis etiological factor, but the current anti-pertussis vaccines do not provide cross-protection. The structural data on any given hypothetical carbohydrate antigen is a prerequisite for further analysis of structure-related activities and their interaction with hosts. H NMR spectra constitute fingerprints of the analyzed glycans and provide unique identity information. The concept of structure-reporter groups has now been augmented by H,C-correlation spectra of the oligosaccharides. The comparative analysis of oligosaccharides (OS) revealed that the hexasaccharide, comprising the α-GlcN, α-GlcA, 4,6-disubstituted-β-Glc, 2,7-disubstituted-l-α-d-Hep, 3,4-disubstituted-l-α-d-Hep and Kdo, constitute the least variable OS segment. This minimal common element in the structure of lipopolysaccharides of could be used to devise a universal cross-protective vaccine component against infections with various bacteria from the genus .