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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two fatty acyl amidases have been partially purified from the slime mold, Dictyostelium discoideum. Their action on lipopolysaccharide derivatives, especially Compound I, has been studied. Amidase I removes specifically the beta-hydroxymyristyl group, which is present on the amino group adjacent to the C-1 phosphate. The product, Compound V, is then a substrate for Amidase II, which removes the remaining beta-hydroxymyristyl group from the amino group in the distal glucosamine ring to give Compound VI. Compound I itself is resistant to Amidase II. Thus, the two enzymes show a high degree of structural specificity. The structure of lipopolysaccharide from the E. coli K-12 mutant is concluded in the light of studies reported in this and the accompanying papers, and this structure is discussed in relation to other bacterial lipopolysaccharides.
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PMID:The structure of lipopolysaccharide from an Escherichia coli heptose-less mutant. III. Two fatty acyl amidases from Dictyostelium discoideum and their action on lipopolysaccharide derivatives. 37 23

The Lipid A from the lipopolysaccharide of Pseudomonas aeruginosa was examined by high-field nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). The backbone structure and the position of phosphate substituents were unambiguously established by one- and two-dimensional 1H, 13C, and 31P NMR techniques on a de-O-acylated Lipid A sample. The Lipid A has a beta-(1,6)-glucosamine disaccharide structure which is substituted by phosphomonoesters through glycosidic bonds at C-1 and at C-4'. The configuration of the glycosidically linked phosphate at position C-1 was identified as alpha which is the same as that of Enterobacterial Lipid A. Chemical analysis revealed that the Lipid A contained 2-hydroxydodecanoic, 3-hydroxydodecanoic, dodecanoic, 3-hydroxydecanoic, and hexadecanoic acids in the approximate molar ratios 2.2:2.0:0.2:0.8:0.4. From 1H NMR and fast atom bombardment (FAB) mass spectrometry on the de-O-acylated Lipid A, it was established that both glucosamine residues were N-acylated by 3-hydroxydodecanoic acid. The identity and positions of the ester bound fatty acids in the intact Lipid A were investigated by negative ion FAB-MS. In addition to the hexaacyl and pentaacyl Lipid A species, a tetraacyl species was identified. Heterogeneity due to hydroxylated and nonhydroxylated dodecanoic acid esters could be uniquely localized to the nonreducing beta-glucosamine residue from the fragmentation pattern observed in the negative ion FAB-MS. The complete structure of the Lipid A from P. aeruginosa will be useful in understanding the determinants responsible for the endotoxin activity of this molecule.
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PMID:Characterization of lipid A from Pseudomonas aeruginosa O-antigenic B band lipopolysaccharide by 1D and 2D NMR and mass spectral analysis. 128 66

The chemical structure of Campylobacter jejuni CCUG 10936 lipid A was elucidated. The hydrophilic backbone of the lipid A was shown to consist of three (1----6)-linked bisphosphorylated hexosamine disaccharides. Neglecting the phosphorylation pattern, a D-glucosamine (2-amino-2-deoxy-D-glucose) disaccharide [beta-D-glucosaminyl-(1----6)-D-glucosamine], a hybrid disaccharide of 2,3-diamino-2,3-dideoxy-D-glucose and D-glucosamine [2,3-diamino-2,3-dideoxy-beta-D-glucopyranosyl-(1----6)-D-glucosamine], and a 2,3-diamino-2,3-dideoxy-D-glucose disaccharide were present in a molar ratio of 1:6:1.2. Although the backbones are bisphosphorylated, heterogeneity exists in the substitution of the polar head groups. Phosphorylethanolamine is alpha-glycosidically bound to the reducing sugar residue of the backbone, though C-1 is also non-stoichiometrically substituted by diphosphorylethanolamine. Position 4' of the non-reducing sugar residue carries an ester-bound phosphate group or is non-stoichiometrically substituted by diphosphorylethanolamine. By methylation analysis it was shown that position 6' is the attachment site for the polysaccharide moiety in lipopolysaccharide. These backbone species carry up to six molecules of ester- and amide-bound fatty acids. Four molecules of (R)-3-hydroxytetradecanoic acid are linked directly to the lipid A backbone (at positions 2, 3, 2', and 3'). Laser desorption mass spectrometry showed that both (R)-3-hydroxytetradecanoic acids linked to the non-reducing sugar unit carry, at their 3-hydroxyl group, either two molecules of hexadecanoic acid or one molecule of tetradecanoic and one of hexadecanoic acid. It also suggested that the (R)-3-(tetradecanoyloxy)-tetradecanoic acid was attached at position 2', whereas (R)-3-(hexadecanoyloxy)-tetradecanoic acid was attached at position 3', or at positions 2' and 3'. Therefore, the occurrence of three backbone disaccharides differing in amino sugar composition and presence of a hybrid disaccharide differentiate the lipid A of this C. jejuni strain from enterobacterial and other lipids A described previously.
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PMID:Structural analysis of the lipid A component of Campylobacter jejuni CCUG 10936 (serotype O:2) lipopolysaccharide. Description of a lipid A containing a hybrid backbone of 2-amino-2-deoxy-D-glucose and 2,3-diamino-2,3-dideoxy-D-glucose. 204 Mar 5

Three novel lipid A analogs, which have an alpha- or beta-glycosidically bound phosphonooxyethyl group instead of the alpha-glycosyl phosphate group of natural lipid A, were synthesized. The first analog (2) had an alpha-phosphonooxyethyl group on the identical acylated disaccharide 4'-phosphate structure found in natural lipid A (from Escherichia coli) and hence differed from the latter only in the nature of the acidic group at position 1. The second one (3) had tetradecanoyl groups in place of the two (R)-3-hydroxytetradecanoyl groups bound to the 2- and 3-hydroxyl function of 2, retaining the alpha-phosphonooxyethyl group. The structure of the third analog (4) was the same as that of 3 except that the phosphonooxyethyl group of the former was beta-oriented. Compounds 2 and 3 exhibited potent activity against Meth A at the same level as natural lipid A, whereas 4 showed less activity. This fact revealed that the glycosidic phosphate is not a prerequisite for the antitumor activity of lipopolysaccharide. It can be replaced with a phosphonooxyethyl group without any loss of activity provided that the alpha-anomeric configuration at C-1 is retained. The replacement of the hydroxytetradecanoyl groups with tetradecanoyl groups does not change the activity either.
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PMID:Synthesis and antitumor activity of lipid A analogs having a phosphonooxyethyl group with alpha- or beta-configuration at position 1. 209 33

Lipid A from Rhodobacter capsulatus 37b4 consists of a D-glucosaminyl-(beta 1-6)-D-glucosamine disaccharide backbone, carrying diphosphorylethanolamine at C-1 of the reducing glucosamine and phosphorylethanolamine at C-4' of the nonreducing glucosamine. 1,4'-Bisphosphorylated lipid A, lacking the polar head groups, was also encountered and contributed to the observed microheterogeneity in the phosphate substitution. The amino functions of both glucosamines are substituted almost entirely by the rare 3-oxotetradecanoic acid, which is a characteristic constituent of lipid A in the genus Rhodobacter. 3-Hydroxydecanoic acid is ester-bound at C-3 and C-3' of the glucosamine disaccharide and the one at the nonreducing glucosamine (C-3') is partially substituted by dodecenoic acid to form an ester-bound diester. In free lipid A, hydroxy groups at C-4 and C-6' of the glucosamine disaccharide are unsubstituted. C-6' being the putative attachment point of the lipopolysaccharide core. The nontoxic Rhodobacter capsulatus lipid A shows extensive serological cross-reaction with the toxic Salmonella lipid A. Structural similarities in the hydrophilic part of both types of lipid A, dissimilarities in the hydrophobic part and their impacts on serologic properties are discussed.
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PMID:Structural analysis of the nontoxic lipid A of Rhodobacter capsulatus 37b4. 271 69

Structural studies were carried out on an acidic O-polysaccharide released by mild acid treatment from the lipopolysaccharide of Pseudomonas aeruginosa IID 1001 (ATCC 27577), which is serologically related to the serotypes Habs O3, Lanyi O1, and Wokatsch O13 in other serological classifications of Pseudomonas aeruginosa. The composition and data from structural analyses including H-NMR and C-NMR measurements, methylation, and Smith degradation showed that the structure of the IID 1001 O-polysaccharide was coincident with that of the Habs O3 and Lanyi O1 antigens (or Wokatsch O13). However, whereas solvolysis of the O-antigen of Habs O3 as well as that of Lanyi O1 by hydrogen fluoride has been reported to yield a reducing trisaccharide, GlcNAc(alpha 1----4)GalNAcA(alpha 1----3)Bac2NAc4Nacyl (acyl represents a 3-hydroxybutanoyl group), hydrogen fluoride hydrolysis of IID 1001 O-polysaccharide yielded a nonreducing trisaccharide with the reducing terminal bacillosamine residue linked at C-1 to the hydroxyl group of its N-acyl substituent, 3-hydroxybutanoic acid. These results, in combination with mass spectral data, led to the most likely structure for the tetrasaccharide repeating unit of the IID 1001 O-polysaccharide, (formula; see text) in which the location of N-acyl groups on bacillosamine residues differs from that in the O-antigens of Habs O3 and Lanyi O1 (or Wokatsch O13).
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PMID:Structure of the O-polysaccharide chain of lipopolysaccharide from Pseudomonas aeruginosa IID 1001 (ATCC 27577). 314 81

The chemical structure of the lipopolysaccharide of a deep-rough mutant (strain I-69 Rd-/b+) of Haemophilus influenzae was investigated. The hydrophilic backbone of lipid A was shown to consist of a beta-(1',6)-linked D-glucosamine disaccharide with phosphate groups at C-1 of the reducing D-glucosamine and at C-4' of the non-reducing one. Four molecules of (R)-3-hydroxytetradecanoic acid were found directly linked to the lipid A backbone, two by amide and two by ester linkage (positions 2,2' and 3,3', respectively). Laser-desorption mass spectrometry showed that both 3-hydroxytetradecanoic acids linked to the non-reducing glucosamine carry tetradecanoic acid at their 3-hydroxyl group, so that altogether six molecules of fatty acid are present in lipid A. The lipopolysaccharide was the first described to contain only one sugar unit linked to lipid A. This, sugar in accordance with a previous report [Zamze et al. (1987) Biochem. J. 245, 583-587], was shown to be a dOclA phosphate. The phosphate group was found at position 4, but the analytical procedures employed (permethylation and methanolysis followed by gas-liquid chromatography/mass spectrometry) also revealed dOclA 5-phosphate. Since a cyclic 4,5-phosphate could be ruled out by 31P-NMR, we conclude that, in this lipopolysaccharide, a mixture of dOclA 4- and 5-phosphate is present. By methylation analysis of the dephosphorylated, deacylated and reduced lipopolysaccharide the attachment site of the dOclA was assigned to position C-6' of the non-reducing glucosamine of lipid A. The anomeric linkages present in the lipopolysaccharide were assessed by 1H-NMR and 13C-NMR of deacylated lipopolysaccharide. The saccharide backbone of this Haemophilus influenzae lipopolysaccharide possesses the following structure: (Formula; see text)
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PMID:Chemical structure of the lipopolysaccharide of Haemophilus influenzae strain I-69 Rd-/b+. Description of a novel deep-rough chemotype. 326 41

Two specific fatty acyl amidases that hydrolyze lipopolysaccharide have been isolated from the slime mold Dictyostelium discoideum. Esterases as well as phosphatases acting on lipid A derivatives were also observed. The first amidase (I) hydrolyzes the fatty amide adjacent to the C-1 phosphate on the disaccharide backbone of lipid A. Amidase II cleaves the distal amide, but only after deacylation of the first site. The range of specificity and the structural determinants important to specificity of the amidases were evaluated in studies of specifically modified derivatives of lipid A. In light of the effects of lipopolysaccharide on the biology of D. discoideum, a role for the amidases and other lipopolysaccharide-specific catabolic enzymes is discussed.
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PMID:Lipases specifically degrading lipopolysaccharide: fatty acyl amidases from Dictyostelium discoideum. 647 5

The substrate specificities of two fatty acyl amidases partially purified from the slime mold Dictyostelium discoideum have been studied. The amidase act on lipopolysaccharide derivatives, such as (4'-O-phosphoryl-N-beta-hydroxymyristyl-D-glucosaminyl)-beta-(1 leads to 6)-N-beta-hydroxymyristyl-D-glucosamine-1-phosphate (III) in a sequential manner. Amidase-I removes the beta-hydroxymyristyl residue present on the amino group adjacent to the 1-phosphate and the product formed is a substrate for amidase-II; the latter removes the remaining beta-hydroxymyristyl residue from the distal amino group. Compound III itself is resistant to amidase-II. Removal of the C-1 or C-4 phosphate groups does not influence recognition by the amidases or their sequential action. Both amidases are specific for long chain fatty amide linkages. Thus, a formyl group on the glucosamine amino group adjacent to the C-1 phosphate is not hydrolyzed by amidase-I; however, this substituent does not hinder the action of amidase-II on the distal fatty acyl amide. The presence of the beta-hydroxyl group in myristyl-amide residues is not required for hydrolysis. Further, while amidase-I requires disaccharide structures for its action, amidase-II acts on monosaccharides as well. Finally, the effects of a variety of substrate analogs and divalent ions on the activity of the enzymes are reported.
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PMID:Fatty acyl amidases from Dictyostelium discoideum that act on lipopolysaccharide and derivatives. II. Aspects of substrate specificity. 710 3

The chemical structure of the lipid A component of the lipopolysaccharide from Vibrio cholerae 95R was studied. After sequential degradation a reduced D-glucosamine disaccharide was isolated from lipid A and, after permethylation, shown by combined gas-liquid chromatography/mass spectrometry to be beta 1,6-linked. The disaccharide is substituted with a phosphate group, ester-bound to the non-reducing glucosamine (GlcN) residue and a pyrophosphorylethanolamine group (PP-Etn) linked to C-1 of the reducing glucosamine residue. This backbone structure is shown in the following formula: P-GlcN(beta 1-6)GlcN-1-PP-Etn. The amino groups of the glucosamine disaccharide are substituted by D-3-hydroxytetradecanoic acid; tetradecanoic, hexadecanoic and a D-3-O-(D-3-hydroxydodecanoyl)-dodecanoic acid residue are linked to hydroxyl groups. A similar fatty acid composition was detected in lipopolysaccharides from Inaba, Ogawa and NAG strains of V. cholerae.
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PMID:The chemical structure of the lipid A component of lipopolysaccharides from Vibrio cholerae. 723 13


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