Pasteurella multocida is an important veterinary pathogen that produces a wide range of lipopolysaccharide (LPS) structures, many of which mimic host glycoproteins. In this study, we complete our analysis of the LPS produced by the P. multocida Heddleston serovars by reporting the LPS structure and the LPS outer core biosynthesis loci of the type strains representing Heddleston serovars 6, 7 and 16. Genetic analysis revealed that the type strains representing serovars 6 and 7 share the same LPS outer core biosynthesis locus which we have designated LPS genotype L4. Comparative bioinformatic analysis revealed that although the serovar 16 type strain contained a different LPS locus, L8, there was a significant degree of nucleotide identity between the L4 and L8 loci. Structural analysis revealed that the LPS glycoforms produced by the L4 and L8 strains all contained the highly conserved inner core produced by all other P. multocida strains examined to date. The residues within the LPS outer core produced by the L4 and L8 strains were either Gal or derivatives of Gal; unlike all other P. multocida Heddleston type strains examined there are no heptosyltransferases encoded in the L4 and L8 outer core biosynthesis loci. The structure of the L4 LPS outer core produced by the serovar 6 type strain consisted of β-Gal-(1-3)-β-N-acetylgalactosamine (GalNAc)-(1-4)-β-GalNAc3OAc-(1-4)-α-GalNAc3OAc-(1-3)-β-Gal, whereas the serovar 7 type strain produced a highly truncated LPS outer core containing only a single β-Gal residue. The structure of the L8 LPS outer core produced by the serovar 16 type strain consisted of β-Gal-(1-3)-β-GalNAc-(1-4)-(α-GalNAc-(1-3)-)-α-GalNAc.

LPS, structure, genetics, core oligosaccharide, Pasteurella multocida

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
5,3,2	aXLDmanHepp
5,3,3,0	%xXEtN
5,3,3	P
5,3	aXLDmanHepp
5,4,4	bDGalp	103.0	71.2	72.6	68.6	74.9	65.8
5,4	bDGlcp
5,6	aDGlcp
5	aXLDmanHepp
4,0,0	xXEtN
4,0	%xXP?
4	P
	aXKdop


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
5,3,2	aXLDmanHepp
5,3,3,0	%xXEtN
5,3,3	P
5,3	aXLDmanHepp
5,4,4	bDGalp	4.52	3.55	3.68	3.94	3.53	3.75-4.11
5,4	bDGlcp
5,6	aDGlcp
5	aXLDmanHepp
4,0,0	xXEtN
4,0	%xXP?
4	P
	aXKdop


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
5,3,2	aXLDmanHepp
5,3,3,0	%xXEtN
5,3,3	P
5,3	aXLDmanHepp
5,4,4	bDGalp	103.0/4.52	71.2/3.55	72.6/3.68	68.6/3.94	74.9/3.53	65.8/3.75-4.11
5,4	bDGlcp
5,6	aDGlcp
5	aXLDmanHepp
4,0,0	xXEtN
4,0	%xXP?
4	P
	aXKdop

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

NCCOP(=O)(O)O[C@@H]1[C@H](O[C@H]2O[C@H]([C@@H](O)CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H](O[C@@H]2[C@H](O)[C@@H](O[C@@H]3[C@H](OP(=O)(O)OP(=O)(O)OCCN)C[C@](O)(C(=O)O)O[C@@H]3[C@H](O)CO)O[C@H]([C@H](CO)O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@H]3O)[C@H]2O[C@@H]2O[C@H](CO)[C@@H](O[C@@H]3O[C@H](CO)[C@H](O)[C@H](O)[C@H]3O)[C@H](O)[C@H]2O)O[C@H]([C@@H](O)CO)[C@H]1O

1627.191 g/mol (C₅₁H₉₃N₂O₅₀P₃)