Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 11521094Journal NLM ID: 9433350Publisher: Maney Publishing
Correspondence: uzaehr
fz-borstel.de
Institutions: Research Center Borstel, Center for Medicine and Biosciences, Borstel, Germany
We here report on the structural analysis of a novel tetra-acyl lipid A (LA (tetra)) isolated from Escherichia coli deep rough (Re)-mutant strain F515. In addition to the biologically active hexa-acyl E. coli- type lipid A (compound 506), this incompletely acylated lipid A was found to be also present in the native LPS. Its structure was studied without further derivatisation by chemical analysis, matrix-assisted laser desorption/ionization mass spectrometry, and one- and two- dimensional (1)H- and (13)C-NMR spectroscopy. It was found to be structurally distinct from the tetra-acyl lipid A biosynthetic precursor Ia (compound 406) in lacking the primary (R)-3- hydroxytetradecanoic acid 14:0(3-OH) in position 3' ester-linked to the 'non-reducing' glucosamine (GlcN II). The hydroxyl group at the (R)-3- hydroxytetradecanoic acid attached to position 2' of GlcN II was found to be substituted by dodecanoic acid (12:0), thus forming a dodecanoyloxytetradecanoyl residue 14:0[3-O(12:0)]. The acylation pattern at the 'reducing' GlcN I was identical to that of compound 406 in having two primary (R)-3-hydroxy tetradecanoic acid residues [14:0(3- OH)] attached to positions 3 (ester-linked) and 2 (amide-linked), respectively. In human mononuclear cells (hMNC) the new LA (tetra) antagonized LPS-induced release of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in a dose-dependent manner with identical antagonistic potency as compared with compound 406. Also like compound 406, it was found to be an agonist in murine macrophage-like J774.1 cells.
Lipopolysaccharide, Escherichia coli, lipid A, mass spectrometry, spectroscopy
Structure type: oligomer
Location inside paper: p.141, fig.6, 406
Trivial name: lipid IV A, lipid IV(A)
Compound class: lipid A, glycolipid
Contained glycoepitopes: IEDB_135394,IEDB_135515,IEDB_141807,IEDB_151531
Methods: 13C NMR, 1H NMR, NMR-2D, TLC, 31P NMR, GLC, mild acid hydrolysis, MALDI-TOF MS, biological assays, composition analysis, NMR-1D, extraction
Comments, role: biosynthetic precursor Ia, synthetic compound 406
Related record ID(s): 31294
NCBI Taxonomy refs (TaxIDs): 562
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There is only one chemically distinct structure:
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