| Author | Search for: Masoud, H.; Search for: Moxon, E.; Search for: Richards, J. |
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| Format | Text, Article |
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| Subject | 31P; bacterial; Bacterial Proteins; biosynthesis; Canada; Carbohydrate Sequence; Carbon; Carbon Isotopes; chemistry; core oligosaccharide; Deuterium; DISACCHARIDE; Electrospray; ELUCIDATION; epitope; Epitopes; Esi Ms; Galactosyltransferases; GENE; genetics; Haemophilus; Haemophilus influenzae; HAEMOPHILUS-INFLUENZAE; Hexoses; IDENTIFICATION; isolation & purification; Isotopes; KDO; LIPOPOLYSACCHARIDE; Lipopolysaccharides; LOCATION; LPS; Magnetic Resonance Spectroscopy; mass spectrometry; MASS-SPECTROMETRY; metabolism; Methylation; Molecular Sequence Data; Molecular Structure; MUTANT; Mutation; NMR; oligosaccharide; Oligosaccharide Epitopes; phosphate; protein; Proteins; SAMPLES; Spectrometry,Mass,Electrospray Ionization; STRAIN; STRUCTURAL; structural elucidation; structure; TRISACCHARIDE; UNIT; Virulence; Virulence Factors |
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| Abstract | Lipopolysaccharide (LPS) oligosaccharide epitopes are major virulence factors of Haemophilus influenzae. The structure of LPS glycoforms of H. influenzae type b strain Eagan containing a mutation in the gene lgtC is investigated. LgtC is involved in the biosynthesis of globoside trisaccharide [alpha-D-Galp-(1-->4)-beta-d-Galp-(1-->4)-beta-D-Glcp-(1-->], an LPS epitope implicated in the virulence of this organism. Glycose and methylation analyses provided information on the composition while electrospray ionization mass spectrometry (ESI-MS) on O-deacylated LPS (LPS-OH) indicated the major glycoform to contain 4 hexoses attached to the common H. influenzae triheptosyl inner-core unit. The structure of the Hex4 glycoform in LPS-OH and core oligosaccharide samples was determined by NMR. It consists of an l-alpha-D-HepIIIp-(1-->2)-[PEtn-->6]-l-alpha-D-HepIIp-(1-->3)-l-alpha-D-He pIp-(1-->5)-[P-->4]-alpha-D-Kdop-(2--> to which a beta-D-Glcp-(1-->4)-alpha-D-Glcp disaccharide unit is extended from HepII at the C-3 position, while HepI and HepIII are substituted at the C-4 and C-2 positions with beta-D-Glcp and beta-D-Galp, respectively. This structure corresponds to that expressed as a subpopulation in the parent strain. 31P NMR studies permitted the identification of subpopulations of LPS containing Kdo substituted at the C-4 position with monophosphate or pyrophosphoethanolamine (PPEtn). HepIII was found to be substituted with either phosphate at the C-4 position or acetate at the C-3 position, but not both of them together in the same subpopulation. The subpopulations containing phosphate and acetate at HepIII and their location have not previously been reported |
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| Publication date | 2008-07-07 |
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| In | |
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| Language | English |
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| NRC number | MASOUD2008A |
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| NPARC number | 9372889 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | e9b57a72-d86c-44ba-abfa-af921896fc6d |
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| Record created | 2009-07-10 |
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| Record modified | 2020-04-15 |
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