Whooping cough is a highly contagious disease caused predominantly by Bordetella pertussis, but it also comprises of a pertussis-like illness caused by B. holmesii. The virulence factors of B. holmesii and their role in the pathogenesis remain unknown. Lipopolysaccharide is the main surface antigen of all Bordetellae. Data on the structural features of the lipopolysaccharide (LPS) of B. holmesii are scarce. The poly- and oligosaccharide components released by mild acidic hydrolysis of the LPS were separated and investigated by 1H and 13C NMR spectroscopy, mass spectrometry, and chemical methods. The structures of the O-specific polysaccharide and the core oligosaccharide of B. holmesii ATCC 51541 have been identified for the first time. The novel pentasaccharide repeating unit of the B. holmesii O-specific polysaccharide has the following structure: {→2)-α-L-Rhap-(1→6)-α-D-Glcp-(1→4)-[β-D-GlcpNAc-(1→3]-α-D-Galp-(1→3)-α-D-GlcpNAc-(1→}n. The SDS-PAGE and serological cross-reactivities of the B. holmesii LPS suggested the similarity between the core oligosaccharides of B. holmesii ATCC 51541 and B. pertussis strain 606. The main oligosaccharide fraction contained a nonasaccharide. The comparative analysis of the NMR spectra of B. holmesii core oligosaccharide fraction with this of the B. pertussis strain 606 indicated that the investigated core oligosaccharides were identical.

Lipopolysaccharide, core, O-antigen, NMR spectroscopy, Bordetella pertussis, pertussis, Bordetella holmesii, Whooping Cough

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
3,4,6	aLRhap	99.0	76.3	70.1	72.7	71.2	17.9
3,4	aDGlcp	100.0	72.7	73.5	69.7	71.1	67.4
3,3,2	Ac	175.1	?
3,3	bDGlcpN	104.8	56.5	74.9	71.0	76.5	61.5
3	aDGalp	99.7	68.7	79.6	77.1	72.5	60.7
2	Ac	175.1	?
	aDGlcpN	96.8	52.7	76.8	71.2	72.6	60.7


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
3,4,6	aLRhap	4.89	4.04	3.95	3.51	3.79	1.34
3,4	aDGlcp	4.92	3.51	3.72	3.57	4.34	3.93-3.97
3,3,2	Ac
3,3	bDGlcpN	4.59	3.64	3.56	3.43	3.43	3.74-3.82
3	aDGalp	5.51	3.93	3.80	4.28	3.98	3.82-3.82
2	Ac
	aDGlcpN	5.03	4.11	4.01	3.82	4.09	3.78-3.78


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
3,4,6	aLRhap	99.0/4.89	76.3/4.04	70.1/3.95	72.7/3.51	71.2/3.79	17.9/1.34
3,4	aDGlcp	100.0/4.92	72.7/3.51	73.5/3.72	69.7/3.57	71.1/4.34	67.4/3.93-3.97
3,3,2	Ac	NMR TSV error 2: unequal length of 13C and 1H datasets
3,3	bDGlcpN	104.8/4.59	56.5/3.64	74.9/3.56	71.0/3.43	76.5/3.43	61.5/3.74-3.82
3	aDGalp	99.7/5.51	68.7/3.93	79.6/3.80	77.1/4.28	72.5/3.98	60.7/3.82-3.82
2	Ac	NMR TSV error 2: unequal length of 13C and 1H datasets
	aDGlcpN	96.8/5.03	52.7/4.11	76.8/4.01	71.2/3.82	72.6/4.09	60.7/3.78-3.78

The spectrum also has 2 signals at unknown positions (not plotted).

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1[C@H](OC[C@H]2O[C@H](O[C@H]3[C@@H](CO)O[C@H](O[C@@H]4[C@@H](NC(C)=O)[C@@H](*)O[C@H](CO)[C@H]4O)[C@H](O)[C@H]3O[C@@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@H]3NC(C)=O)[C@H](O)[C@@H](O)[C@@H]2O)O[C@@H](C)[C@H](O)[C@H]1O

876.812 g/mol (C₃₄H₅₆R₂N₂O₂₄, R = next and previous repeats, not counted in mol weight)