RÉSUMÉ
Bacteria are an inimitable source of new glyco-structures potentially useful in medicinal and environmental chemistry. Lipopolysaccharides (LPS; endotoxins) are the major components of the outer membrane of Gram-negative bacteria; being exposed toward the external environment they can undergo structural changes and thus, they often possess peculiar chemical features that allow them to thrive in harsh chemical and physical environments. Marine bacteria have evolved and adapted over millions of years in order to succeed in different environments, finding a niche for their survival characterized by severe physical or chemical parameters. The present work focuses on the structural investigation of the LPS from Loktanella rosea, a marine Gram-negative bacterium. Through chemical analysis, 2D nuclear magnetic resonance and matrix-assisted laser desorption ionization mass spectrometry investigations, a unique LPS carbohydrate backbone has been defined. The lipid A skeleton consists of a trisaccharide backbone lacking the typical phosphate groups and is characterized by two beta-glucosamines and an alpha-galacturonic acid. The core region is built up of three ulosonic acids, with two 3-deoxy-d-manno-oct-2-ulopyranosonic acid residues, one of which is carrying a neuraminic acid. This carbohydrate structure is an exceptional variation from the typical architectural skeleton of endotoxins which consequently implies a very different biosynthesis.
Sujet(s)
Lipopolysaccharides/composition chimique , Rhodobacteraceae/composition chimique , Conformation des glucides , Séquence glucidique , Spectroscopie par résonance magnétique , Données de séquences moléculaires , Spectrométrie de masse MALDIRÉSUMÉ
The O-chain polysaccharide of the lipopolysaccharide from the halophilic marine bacterium Pseudoalteromonas carrageenovora IAM 12662T was characterized. The structure was studied by means of chemical analysis and 2D NMR spectroscopy of the de-O-acylated lipopolysaccharide and shown to be the following:Col is colitose, 3,6-di-deoxy-L-xylo-hexose.
Sujet(s)
Lipopolysaccharides/composition chimique , Pseudoalteromonas/composition chimique , Conformation des glucides , Séquence glucidique , Lipopolysaccharides/isolement et purification , Spectroscopie par résonance magnétique , Modèles moléculaires , Données de séquences moléculairesRÉSUMÉ
The structure of the carbohydrate backbone of the lipooligosaccharide (LOS) of the marine bacterium Arenibacter certesii strain KMM 3941(T) has been elucidated. The structure was obtained by means of compositional analysis, matrix-assisted laser desorption/ionization mass spectrometry and complete 1H and 13C and 31P NMR spectroscopy. It shows novel and interesting aspects and is the first description of Arenibacter lipopolysaccharides. Strong and mild alkaline treatments, to fully deacylate and only to O-deacylate the LOS were performed in order to determine the core structure. The core consists of a mixture of species differing by the presence of a non-stoichiometric alpha-d-rhamnose residue. The Kdo unit is substituted at O-5 by alpha-mannose and at O-4 by a alpha-galactosyluronic acid phosphate. The lipid A is constituted by a bis-phosphorylated disaccharide unit composed by a 2,3-diamino-2,3-dideoxy-beta-d-glucopyranose (DAG) residue as non-reducing end and a GlcN as reducing end.
Sujet(s)
Flavobacteriaceae/composition chimique , Lipopolysaccharides/composition chimique , Conformation des glucides , Séquence glucidique , Flavobacteriaceae/croissance et développement , Spectroscopie par résonance magnétique , Biologie marine , Données de séquences moléculaires , Structure moléculaire , Spectrométrie de masse MALDIRÉSUMÉ
The structure of the phenol-soluble polysaccharide from Pseudoalteromonas rubra type strain ATCC 29570T has been elucidated using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, gNOESY, ROESY, 1H,13C gHMQC and gHMBC experiments. It is concluded that the trisaccharide repeating unit of the polysaccharide has the following structure: [carbohydrate structure: see text] where Sug is 2-acetamido-2,6-dideoxy-D-xylo-hexos-4-ulose, Am is acetimidoyl and Acyl is a malic acid residue, which is O-acetylated in approximately 70% of the units.
Sujet(s)
Antigènes O/composition chimique , Pseudoalteromonas/composition chimique , Séquence glucidique , Isotopes du carbone , Hydrogène , Données de séquences moléculaires , Résonance magnétique nucléaire biomoléculaireRÉSUMÉ
An acidic O-specific polysaccharide (PS) of the agar-digesting bacterium Shewanella japonica with the type strain KMM 3299(T) was obtained by mild acid hydrolysis of the lipopolysaccharide. The polysaccharide was studied by component analysis, methylation analysis, (1)H and (13)C NMR spectroscopy, including 2D NMR experiments. The PS was determined to have the following structure involving three unusual amino sugars:
Sujet(s)
Fucose/analogues et dérivés , Antigènes O/composition chimique , Shewanella/composition chimique , Shewanella/classification , Séquence glucidique , Fucose/analyse , Fucose/composition chimique , Spectroscopie par résonance magnétique , Données de séquences moléculairesRÉSUMÉ
The structure of an acidic polysaccharide from Pseudoalteromonas aliena type strain KMM 3562(T) has been elucidated. The polysaccharide was studied by component analysis, (1)H and (13)C NMR spectroscopy, including 2D NMR experiments. A (1)H, (13)C band-selective constant-time heteronuclear multiple-bond connectivity experiment was used to determine amide linkages, between serine and uronic acid (UA) residues, via (3)J(H,C) correlations between Ser-alphaH and UA-C-6. It was found that the polysaccharide consists of pentasaccharide repeating units with the following structure: [carbohydrate structure]; see text.
Sujet(s)
Polyosides/composition chimique , Pseudoalteromonas/composition chimique , Pseudoalteromonas/classification , Sérine/analyse , Séquence glucidique , Concentration en ions d'hydrogène , Spectroscopie par résonance magnétique , Données de séquences moléculaires , Polyosides/isolement et purificationRÉSUMÉ
The complete novel structure of the components of the core oligosaccharide fraction from the LOS of the halophilic marine bacterium Pseudoalteromonas carrageenovora was characterized. The fully de-acylated lipooligosaccharide was studied by means of compositional analysis, matrix-assisted laser desorption/ionization mass spectrometry and complete (1)H and (13)C and (31)P NMR spectroscopy. The core oligosaccharide is composed by a mixture of species differing for the length of the sugar chain and the phosphorylation pattern: [carbohydrate structure]; see text. All sugars are D-pyranoses. Hep is L-glycero-D-manno-heptose, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, P is phosphate, residues and substituents in italic are not stoichiometrically linked.
Sujet(s)
Lipopolysaccharides/composition chimique , Pseudoalteromonas/composition chimique , Pseudoalteromonas/classification , Acylation , Séquence glucidique , Lipopolysaccharides/isolement et purification , Spectroscopie par résonance magnétique , Données de séquences moléculaires , Spectrométrie de masse MALDIRÉSUMÉ
The structure of an acidic polysaccharide from Pseudoalteromonas atlantica strain 14165 containing 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac) has been elucidated. The polysaccharide was studied by 1H and 13C NMR spectroscopy, including 2D experiments, along with sugar and methylation analyses. After a selective hydrolysis a modified polysaccharide devoid of its side chain could be isolated. It was found that the polysaccharide has pentasaccharide repeating units with following structure: [structure: see text].
Sujet(s)
Agar-agar/métabolisme , Polyosides bactériens/composition chimique , Pseudoalteromonas/composition chimique , Pseudoalteromonas/classification , Acides sialiques/analyse , Séquence glucidique , Spectroscopie par résonance magnétique , Données de séquences moléculaires , Pseudoalteromonas/métabolisme , Acides sialiques/composition chimiqueRÉSUMÉ
Novel lipooligosaccharide components were isolated and identified from the lipooligosaccharide fraction of the halophilic marine bacterium Pseudoalteromonas issachenkonii type strain KMM 3549T. The complete structure was achieved by chemical analysis, 2D NMR spectroscopy and MALDI mass spectrometry as the following: [carbohydrate formula see text] All sugars are d-pyranoses. Hep is L-glycero-D-manno-heptose, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, P is phosphate, residues and substituents in italic are not stoichiometrically linked. In addition, by MALDI mass spectrometry of the intact LOS, the lipid A moiety was also identified as a mixture of penta-, tetra- and triacylated species.
Sujet(s)
Bacillaceae/composition chimique , Lipopolysaccharides/composition chimique , Pseudoalteromonas/composition chimique , Conformation des glucides , Séquence glucidique , Lipopolysaccharides/isolement et purification , Spectroscopie par résonance magnétique , Données de séquences moléculaires , Pseudoalteromonas/classification , Spectrométrie de masse MALDI/méthodes , Spécificité du substratRÉSUMÉ
The O-specific polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of the marine bacterium Shewanella fidelis type strain KMM 3582T and studied by sugar analysis along with 1H and 13C NMR spectroscopy including one-dimensional NOE in difference mode and two-dimensional experiments. The polysaccharide was found to consist of linear tetrasaccharide repeating units containing Nepsilon-[(S)-1-carboxyethyl]-Nalpha-(D-galacturonoyl)-L-lysine and having the following structure: [See text.] The amide of D-galacturonic acid with Nepsilon-[(S)-1-carboxyethyl]-L-lysine ('alaninolysine', 2S,8S-AlaLys) was found for the first time in nature as a component of the O-specific polysaccharide of Providencia rustigianii O14 (Carbohydr. Res. 2003, 338, 1009-1016).
Sujet(s)
Lysine/analogues et dérivés , Lysine/composition chimique , Antigènes O/composition chimique , Polyosides/composition chimique , Shewanella/composition chimique , Acide acétique/composition chimique , Acétylation , Amides/composition chimique , Séquence glucidique , Isotopes du carbone , Glycosylation , Hydrolyse , Lipopolysaccharides/composition chimique , Lipopolysaccharides/isolement et purification , Données de séquences moléculaires , Résonance magnétique nucléaire biomoléculaire , Antigènes O/immunologie , Polyosides/immunologieRÉSUMÉ
The chemical structures of polysaccharides and LPS core oligosaccharides, isolated from various Gram-negative marine bacteria from the genera Pseudoalteromonas and Shewanella belonging to the Alteromonadaceae family and gamma-subclass of Proteobacteria, are reviewed. The polysaccharides are distinguished by the acidic character (e.g., due to the presence of hexuronic and aldulosonic acids and their derivatives) and the occurrence of unusual sugars, including N-acyl derivatives of 6-deoxyamino sugars, such as N-acetyl-D-quinovosamine, N-acetyl-L-fucosamine and N-acetyl-6-deoxy-L-talosamine, and higher sugars like 2,6-dideoxy-2-acetamido-4-C-(3'-carboxamide-2',2'-dihydroxypropyl)-D-galactopyranose (shewanellose). Many constituent sugars have various uncommon non-sugar substituents, such as alanine, formic, lactic and hydroxybutyric acids, sulfate, phosphate, and 2-aminopropane-1,3-diol.
Sujet(s)
Bactéries à Gram négatif/métabolisme , Oligosaccharides/composition chimique , Polyosides bactériens/composition chimique , Proteobacteria/métabolisme , Conformation des glucides , Séquence glucidique , Lipopolysaccharides/composition chimique , Données de séquences moléculaires , Antigènes O/composition chimique , Pseudoalteromonas/métabolisme , Shewanella/métabolismeRÉSUMÉ
An acidic polysaccharide was isolated from Pseudoalteromonas flavipulchra type strain NCIMB 2033(T) and found to consist of 6-deoxy-L-talose (L-6dTal), D-galactose and 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo). The identities of the monosaccharides were ascertained by sugar analysis and 1D 1H and 13C NMR spectroscopy in conjunction with 2D COSY, TOCSY, ROESY and 1H, 13C HMQC experiments, which enabled determination of the following structure of the trisaccharide repeating unit of the polysaccharide:-->3)-alpha-L-6dTalp4Ac-(1-->3)-beta-D-Galp-(1-->7)-alpha-Kdop-(2-->.
Sujet(s)
Polyosides/composition chimique , Pseudoalteromonas/composition chimique , Désoses/composition chimique , Galactose/composition chimique , Hexose/composition chimique , Spectroscopie par résonance magnétique , Oses acides/composition chimiqueRÉSUMÉ
The structure of the phenol-soluble polysaccharide from Shewanella putrefaciens strain A6 has been elucidated. Chemical modifications of the polymer in conjunction with 1H and 13C NMR spectroscopy, including 2D techniques, were employed in the analysis. It is concluded that the repeating unit is composed of two nine-carbon sugars as follows: -->4)-alpha-NonpA-(2-->3)-beta-Sugp-(1--> where alpha-NonpA is 5-acetamido-7-acetamidino-8-O-acetyl-3,5,7,9-tetradeoxy-L-glycero-alpha-D-galacto-non-2-ulosonic acid (8eLeg) and beta-Sugp is 2-acetamido-2,6-dideoxy-4-C-(3'-carboxamide-2',2'-dihydroxypropyl)-beta-D-galactopyranose, with the proposed name Shewanellose (She).