A polysaccharide containing the residues of 2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid (Kdn) was found in the cell wall of the Brevibacterium casei strain AEI Ac-2114T . The polymer structure was elucidated by analyzing one-dimensional spectra of 1H and 13C NMR and bidimentional experiments 1H/13C-COSY, TOCSY, 1H/13C-gHSQC, and 1H/13C-gHMBC. The polymer is built up of the 2--> 4-linked Kdn residues substituted by beta-D-Glcp residues at 8- and 9-hydroxyls; such a polymer with disubstituted Kdn residues was found for the first time. A glycosylated teichoic acid of the 1,3-poly(glycerophosphate) type was also identified among other anionic polymers of cell wall. 相似文献
A hexasaccharide 1-phosphate polymer of original structure and two teichoic acids (TA) belonging to different structural types were found in Arthrobacter uratoxydans VKM Ac-1979T cell wall. The poly(hexasaccharide 1-phosphate) combines features of teichuronic acids and glycosyl 1-phosphate polymers, and its structure has never been reported earlier. Its composition includes residues of α- and β-D-glucuronic acid as well as α-D-galacto-, β-D-gluco-, α-D-mannopyranose, and 6-O-acetylated 2-acetamido-2-deoxy-α-D-glucopyranose. The phosphodiester bond in the polymer joins the glycoside hydroxyl of α-D-glucuronic acid and O6 of α-D-galactopyranose. TA 1 is β-D-glucosylated 1,3-poly(glycerol phosphate), and TA 2 is 3,6-linked poly[α-D-glucosyl-(1→2)-glycerol phosphate]. The phosphate-containing polymers were studied by chemical methods and on the basis of one-dimensional 1H-, 13C-, and 31P-NMR spectra, homonuclear two-dimensional 1H/1H COSY, TOCSY, ROESY, and heteronuclear 1H/13C HSQC, HSQC-TOCSY, HMBC, and 1H/31P HMBC experiments. The set and structure of the polymers revealed as well as the cell wall sugars (galactose, glucose, mannose, glucosamine) and glycerol can be used in microbiological practice for taxonomic purposes. 相似文献
The cell wall of the model actinomycete Streptomyces coelicolor M145 has recently been shown to contain the novel glycopolymer teichulosonic acid. The major building block of this polymer is 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (Kdn), suggesting initial clues about the genetic control of biosynthesis of this cell wall component. Here, through genome mining and gene knockouts, we demonstrate that the sco4879–sco4882 genomic region of S. coelicolor M145 is necessary for biosynthesis of teichulosonic acid. Specifically, mutants carrying individual knockouts of sco4879, sco4880 and sco4881 genes do not produce Kdn-containing glycopolymer and instead accumulate the minor cell wall component poly(diglycosyl 1-phosphate). Our studies provide evidence that this region is at least partly responsible for biosynthesis of Kdn, whereas flanking genes might control the other steps of teichulosonic acid formation. 相似文献
The subject of the present review is the structural diversity and abundance of cell wall teichuronic and teichulosonic acids
of representatives of the order Actinomycetales. Recently found teichulosonic acids are a new class of natural glycopolymers
with ald-2-ulosonic acid residues: Kdn (3-deoxy-D-glycero-D-galacto-non-2-ulosonic acid) or di-N-acyl derivatives of Pse (5,7-diamino-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic or pseudaminic acid) as the obligatory component. The structures of teichuronic and teichulosonic acids are
presented. Data are summarized on the occurrence of the glycopolymers of different nature in the cell wall of the studied
actinomycetes. The biological role of the glycopolymers and their possible taxonomic implication are discussed. The comprehensive
tables given in the Supplement show 13C NMR spectroscopic data of teichuronic and teichulosonic acids obtained by the authors. 相似文献
The structures of cell wall anionic carbohydrate-containing polymers in Streptomyces melanosporofaciens VKM Ac-1864T and phylogenetically close organisms—S. hygroscopicus subsp. hygroscopicus VKM Ac-831T, S. violaceusniger VKM Ac-583T, S. endus VKM Ac-1331T, S. endus VKM Ac-129, and S. rutgersensis subsp. castelarensis VKM Ac-832T—have been comparatively studied by chemical and NMR spectroscopic methods. The natural polymer of a new, previously unknown structure, Kdn (3-deoxy-D-glycero-D-galacto-non-2-ulopyranosonic acid) with β-galactose residues at C-9, has been found in the cell walls of all the strains under study. The cell walls of all the studied organisms contain three teichoic acids (TA): a predominant TA (1,3-poly(glycerol phosphate) with N-acetylated α-glucosaminyl substitutes by C-2 of glycerol, and minor TAs, 1,3-and 2,3-poly(glycerol phosphate) polymers without substitution. Their chains have O-acetyl and O-lysyl groups. Microorganisms of the above-mentioned species differ in the number of α-glucosaminyl substitutes and in the degree of their acetylation in the predominant teichoic acid. 相似文献
A high-molecular-mass polysaccharide galactan (M 2000 kDa) was isolated from flax at the stage of cell wall thickening of the bast fiber development. The polymer structure was studied by 1H NMR spectroscopy and MALDI TOF mass spectrometry. It is built up of Gal (59%), Rha (15%), GalA (23%), and Ara (3%) residues. The galactan backbone consists of successively alternating monomer disaccharide units (→ 4GalA1 → 2Rha1 →)n and is similar in its structure to the backbone of rhamnogalacturonan-1 (RG-I). Rhamnose residues bear in position 4 β-(1 → 4)-galactose side chains of various lengths with a polymerization degree of up to 28 or higher. A part of the side chains have branchings. 相似文献
Radiolabeled d-[1-3H]glucose was fed by imbibition under sterile conditions to bean (Phaseolus vulgaris L.) seeds. After 72 and 96 hours of feeding, the 3H was located in uronic acid and pentose residues as well as hexose residues of cell wall polysaccharides in growing hypocotyl and root. Free myo-inositol present in cotyledons, hypocotyl, and root also contained 3H, showing that de novo synthesis of myo-inositol from [1-3H]glucose did occur during the first 72 hours of germination. More than 90% of the labeled, free myo-inositol was present in the cotyledons. The 3H percentage in trifluoroacetic acid-soluble arabinose residues of cell wall polysaccharides from 72-hour-old bean hypocotyls was only half of their mole percentage. On the other hand, 3H percentages in hexose residues were higher than their mole percentages. The results suggest that myo-inositol is synthesized from reserve sugars during the very early stages of germination, and that the newly synthesized myo-inositol, as well as that stored in cotyledons, can be used for the construction of new hypocotyl and root cell wall polysaccharides after conversion into uronic acids and pentoses via the myo-inositol oxidation pathway. 相似文献
Teichoic acid and disaccharide-1-phosphate polymer were identified in the cell walls of Bacillus subtilis subsp. subtilis VKM B-501T. The teichoic acid represents 1,3-poly(glycerol phosphate) 80% substituted by α-D-glucopyranose residues at O-2 of glycerol. The linear repeating unit of disaccharide-1-phosphate polymer contains the residues of β-D-glucopyranose, N-acetyl-α-D-galactosamine, and phosphate and has the following structure: -6)-β-D-Glcp-(1→3)-α-D-GalpNAc-(1-P-. The structures of two anionic polymers were determined by chemical and NMR-spectroscopic methods. The 1H- and 13C-NMR spectral data on disaccharide-1-phosphate polymer are presented for the first time. 相似文献
The capsular polysaccharide of Klebsiella SK1 was investigated by methylation analysis, Smith degradation, and 1H NMR spectroscopy. The oligosaccharides (P1 and P2) obtained by bacteriophage ΦSK1 degradation of the polymer were studied by methylation analysis, and 1D- and 2D-NMR spectroscopy. The resulting data showed that the patent repeating unit is a branched pentasaccharide having a structure identical to the revised structure recently proposed for Klebsiella serotype K8 capsular polysaccharide. The 2D-NMR data showed that one third of the glucuronic acid residues in the SK1 polymer are acetylated at O-2, O-3, or O-4. FABMS studies confirmed the presence of monoacetylated glucuronic acid residues. Thus, the relationship between the Klebsiella K8 and SK1 polymers is akin to that found for Klebsiella polysaccharides K30 and K33, which have been typed as serologically distinct yet their structures differ only in the degree of acetylation. 相似文献
The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O12. Its structure was studied by sugar analysis using GLC of the alditol acetates and (S)-2-octyl glycosides, methylation analysis, Smith degradation, and 1H and 13C NMR spectroscopy, including 2D 1H-1H COSY, TOCSY, ROESY, 1H-13C HSQC, and HMBC experiments. It was found that the polymer is a neutral heteropolysaccharide and has a branched heptasaccharide repeating unit with the following structure: 相似文献
Cell walls of the Basidiomycete fungus Polyporus tumulosus (Cooke) were fractionated, and the polysaccharide content of the fractions investigated. The major constituents of the cell wall include four polysaccharides, chitin, a β-1, 3-glucan and the alkali soluble α-glucan and xylomannan.The glucan is highly dextrotatory with an [α]D21 of + 221° and gave on partial acid hydrolysis and acetolysis an homologous series of oligosaccharides. The disaccharide was shown to be nigerose 3-0-α-D-glucopyranosyl-D-glucose. Periodate oxidation and methylation studies provided supporting evidence that the polysaccharide is an essentially unbranched polymer of 1,3-linked glucose residues.The other alkali-soluble polysaccharide, a xylomannan, is a polymer of mannose and xylose in the approximate molar proportions of 1.2:1. It has an [α]D = + 56° and on partial acid hydrolysis and acetolysis gave an homologous series of 1,3-linked mannodextrins but no oligosaccharides containing xylose were obtained. An α-1,3-linked mannan was prepared from the xylomannan by degradation with mild acid or by degradation of the periodate-oxidased and reduced xylomannan. The structure therefore is visualised as having a backbone of 1,3-linked mannan, to which xylose residues are attached. Methylation studies showed that branching occurs at C-4 of the mannopyranose units; the presence of 2,3-di-o-methyl-d-xylose in the hydrolysate of the methylated polysaccharide indicated that some of the xylose residues are 1,4-linked. The possible structure of the fungal cell wall is discussed in the light of the results obtained. 相似文献
A polysaccharide was isolated by GPC after mild acid treatment of the lipopolysaccharide of Vibrio vulnificus CECT4602 and found to contain l-Rha, d-GlcpNAc and 2-acetamido-2,3,6-trideoxy-3-(3-hydroxybutanoylamino)-l-mannose (l-RhaNAc3NHb). GLC analysis of the trifluoroacetylated (S)-2-octyl esters derived by full acid hydrolysis of the polysaccharide showed that ∼80% of the 3-hydroxybutanoic acid has the S configuration and ∼20% the R configuration. The following structure of the polysaccharide was established by 1H and 13C NMR spectroscopies, including 2D ROESY and 1H/13C HMBC experiments: 相似文献
Gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy were used to study the metabolism of deuterated n-alkanes (C6 to C12) and 1-13C-labeled n-hexane by a highly enriched sulfate-reducing bacterial culture. All substrates were activated via fumarate addition to form the corresponding alkylsuccinic acid derivatives as transient metabolites. Formation of d14-hexylsuccinic acid in cell extracts from exogenously added, fully deuterated n-hexane confirmed that this reaction was the initial step in anaerobic alkane metabolism. Analysis of resting cell suspensions amended with 1-13C-labeled n-hexane confirmed that addition of the fumarate occurred at the C-2 carbon of the parent substrate. Subsequent metabolism of hexylsuccinic acid resulted in the formation of 4-methyloctanoic acid, and 3-hydroxy-4-methyloctanoic acid was tentatively identified. We also found that 13C nuclei from 1-13C-labeled n-hexane became incorporated into the succinyl portion of the initial metabolite in a manner that indicated that 13C-labeled fumarate was formed and recycled during alkane metabolism. Collectively, the findings obtained with a sulfate-reducing culture using isotopically labeled alkanes augment and support the previously proposed pathway (H. Wilkes, R. Rabus, T. Fischer, A. Armstroff, A. Behrends, and F. Widdel, Arch. Microbiol. 177:235-243, 2002) for metabolism of deuterated n-hexane by a denitrifying bacterium. 相似文献
The structures of cell wall glycopolymers from the type strains of three Actinoplanes species were investigated using chemical methods, NMR spectroscopy, and mass spectrometry. Actinoplanes digitatis VKM Ac-649T contains two phosphate-containing glycopolymers: poly(diglycosyl-1-phosphate) →6)-α-D-GlcpNAc-(1-P-6)-α-D-GlcpN-(1→ and teichoic acid →1)-sn-Gro-(3-P-3)-β-[β-D-GlcpNAc-(1→2]-D-Galp-(1→. Two glycopolymers were identified in A. auranticolor VKM Ac-648T and A. cyaneus VKM Ac-1095T: minor polymer–unsubstituted 2,3-poly(glycerol phosphate), widely abundant in actinobacteria (Ac-648T), and mannan with trisaccharide repeating unit →2)-α-D-Manp-(1→2)-α-D-Manp(1→6)-α-D-Manp-(1→(Ac-1095T). In addition, both microorganisms contain a teichuronic acid of unique structure containing a pentasaccharide repeating unit with two residues of glucopyranose and three residues of diaminouronic acids in D-manno- and/or D-gluco-configuration. Each of the strains demonstrates peculiarities in the structure of teichuronic acid with respect to the ratio of diaminouronic acids and availability and location of O-methyl groups in glucopyranose residues. All investigated strains contain a unique set of glycopolymers in their cell walls with structures not described earlier for prokaryotes. 相似文献
1H, 2H, 13C, and 81Br nmr measurements of mixtures of poly-L -lysine hydrobromide with water have been carried out over a range of temperatures and water contents. When n (number of molecules of water per residue) ~13 at room temperature, a transition occurs from a gel to a liquid phase. The liquid phase contains polymer molecules that are flexible, but contain more intramolecular structure than the same molecules in trifluoracetic acid solution. The gel phase contains junction zones of hexagonally packed α-helices, linked by flexible regions of polypeptide chain. The α-helical residues impart to their associated water molecules a slight anisotropy of motion, which is dectable by 2H nmr. These residues bind up to about seven molecules of water each; the other six required to complete the gel–liquid transition space out the polymer molecules, allowing increased segmental motion of the residues in the flexible regions. This increased motion reduces the energy of the flexible regions and thus increases the proportion of residues in them (increasing the temperature has the same effect); the transition occurs when insufficient residues remain in the α-helical junction zones. 相似文献
The bacterial immunoglobulin-like (Big) domain is one of the prevalent domain types, which facilitates cell–cell adhesion by assembling into multi-domain architectures. We selected a four Big_2 domain protein (named ‘Arig’) from a Gram positive, Paenarthrobacter aurescens TC1 (known earlier as Arthrobacter aurescens TC1). In an attempt to characterize structural and ligand-binding features of individual Big_2 domains, we have cloned, overexpressed, isolated and purified the second Big_2 domain of Arig along with a few of its adjacent Big_2 domain residues (residue 143 to 269) referred to as ‘Arig2’. The 13C/15N-doubly-labeled His-tagged Arig2 (133 residues long) showed an ordered conformation as revealed by the well dispersed 2D [15N-1H]-HSQC spectrum. Subsequently, a suite of heteronuclear 3D NMR experiments has enabled almost complete 1H, 13C and 15N NMR resonance assignments of Arig2. 相似文献
We present a general approach in 1H-detected 13C solid-state NMR (SSNMR) for side-chain signal assignments of 10-50 nmol quantities of proteins using a combination of a high magnetic field, ultra-fast magic-angle spinning (MAS) at ~80 kHz, and stereo-array-isotope-labeled (SAIL) proteins [Kainosho M. et al., Nature 440, 52–57, 2006]. First, we demonstrate that 1H indirect detection improves the sensitivity and resolution of 13C SSNMR of SAIL proteins for side-chain assignments in the ultra-fast MAS condition. 1H-detected SSNMR was performed for micro-crystalline ubiquitin (~55 nmol or ~0.5mg) that was SAIL-labeled at seven isoleucine (Ile) residues. Sensitivity was dramatically improved by 1H-detected 2D 1H/13C SSNMR by factors of 5.4-9.7 and 2.1-5.0, respectively, over 13C-detected 2D 1H/13C SSNMR and 1D 13C CPMAS, demonstrating that 2D 1H-detected SSNMR offers not only additional resolution but also sensitivity advantage over 1D 13C detection for the first time. High 1H resolution for the SAIL-labeled side-chain residues offered reasonable resolution even in the 2D data. A 1H-detected 3D 13C/13C/1H experiment on SAIL-ubiquitin provided nearly complete 1H and 13C assignments for seven Ile residues only within ~2.5 h. The results demonstrate the feasibility of side-chain signal assignment in this approach for as little as 10 nmol of a protein sample within ~3 days. The approach is likely applicable to a variety of proteins of biological interest without any requirements of highly efficient protein expression systems. 相似文献
Fourteen ursolic acid and oleanolic acid saponins with N-acetyl-β-d-glucosamine, and (1→4)-linked and (1→6)-linked N-acetyl-β-d-glucosamine oligosaccharide residues were synthesized in a convergent manner. The structures of all compounds were confirmed by 1H NMR and 13C NMR spectroscopy and by mass spectrometry, and their cytotoxic activities were assayed in three cancer cell lines. Only oleanolic acid-3-yl β-d-GluNAc showed significant cytotoxicity against HL-60 and BGC-823. 相似文献