Conserved Structural Features of Core Oligosaccharides among the Lipopolysaccharides of Respiratory Pathogens from the Genus <i>Bordetella</i> Analyzed Exclusively by NMR Spectroscopy

• Main Authors: Karolina Ucieklak, Sabina Koj, Tomasz Niedziela
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Bordetella</i> spp.; lipopolysaccharide; core oligosaccharide; NMR spectroscopy; whooping cough; pertussis
• Online Access: https://www.mdpi.com/1422-0067/22/3/1029
• ISSN: 1661-6596; 1422-0067

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. <i>B. pertussis</i>, <i>B. parapertussis</i>, <i>B. bronchiseptica,</i> and <i>B. holmesii</i>, are mammalian respiratory pathogens, having substantial economic impact on human health and agriculture. <i>B. pertussis</i> is responsible for whooping cough (pertussis) and <i>B. holmesii</i> 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. ¹H NMR spectra constitute fingerprints of the analyzed glycans and provide unique identity information. The concept of structure-reporter groups has now been augmented by ¹H,¹³C-correlation spectra of the <i>Bordetella</i> oligosaccharides. The comparative analysis of <i>Bordetellae</i> oligosaccharides (OS) revealed that the hexasaccharide, comprising the α-Glc<i>p</i>N, α-Glc<i>p</i>A, 4,6-disubstituted-β-Glc<i>p</i>, 2,7-disubstituted-<span style="font-variant: small-caps;">l</span>-α-<span style="font-variant: small-caps;">d</span>-Hep<i>p</i>, 3,4-disubstituted-<span style="font-variant: small-caps;">l</span>-α-<span style="font-variant: small-caps;">d</span>-Hep<i>p,</i> and Kdo, constitute the least variable OS segment. This minimal common element in the structure of lipopolysaccharides of <i>Bordetellae</i> could be used to devise a universal cross-protective vaccine component against infections with various bacteria from the genus <i>Bordetella</i>.