(1 → 2) and (1 → 6)-linked β-d-galactofuranan of microalga Myrmecia biatorellae, symbiotic partner of Lobaria linita

Cordeiro, Lucimara M.C.; Beilke, Flávio; Bettim, Franciele Lima; Reinhardt, Vanessa de Fátima; Rattmann, Yanna Dantas; Iacomini, Marcello

doi:10.1016/j.carbpol.2012.07.069

Cited by 12 publications

(5 citation statements)

References 36 publications

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“…This correlation was confirmed on the 1 H/ 13 C HMBC spectrum. Thus, these connectivities and 1 H and 13 C chemical shifts are consistent with the literature values for a β(1−>6)-galactofuranose polymer [43]. Again, the structure of the EPS released into the culture medium was identical to that of the capsular galactan [10].…”

Section: Resultssupporting

confidence: 88%

Characterization of Free Exopolysaccharides Secreted by Mycoplasma mycoides Subsp. mycoides

et al. 2013

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Contagious bovine pleuropneumonia is a severe respiratory disease of cattle that is caused by a bacterium of the Mycoplasma genus, namely Mycoplasma mycoides subsp. mycoides (Mmm). In the absence of classical virulence determinants, the pathogenicity of Mmm is thought to rely on intrinsic metabolic functions and specific components of the outer cell surface. One of these latter, the capsular polysaccharide galactan has been notably demonstrated to play a role in Mmm persistence and dissemination. The free exopolysaccharides (EPS), also produced by Mmm and shown to circulate in the blood stream of infected cattle, have received little attention so far. Indeed, their characterization has been hindered by the presence of polysaccharide contaminants in the complex mycoplasma culture medium. In this study, we developed a method to produce large quantities of EPS by transfer of mycoplasma cells from their complex broth to a chemically defined medium and subsequent purification. NMR analyses revealed that the purified, free EPS had an identical β(1−>6)-galactofuranosyl structure to that of capsular galactan. We then analyzed intraclonal Mmm variants that produce opaque/translucent colonies on agar. First, we demonstrated that colony opacity was related to the production of a capsule, as observed by electron microscopy. We then compared the EPS extracts and showed that the non-capsulated, translucent colony variants produced higher amounts of free EPS than the capsulated, opaque colony variants. This phenotypic variation was associated with an antigenic variation of a specific glucose phosphotransferase permease. Finally, we conducted in silico analyses of candidate polysaccharide biosynthetic pathways in order to decipher the potential link between glucose phosphotransferase permease activity and attachment/release of galactan. The co-existence of variants producing alternative forms of galactan (capsular versus free extracellular galactan) and associated with an antigenic switch constitutes a finely tuned mechanism that may be involved in virulence.

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Section: Resultssupporting

confidence: 88%

Characterization of Free Exopolysaccharides Secreted by Mycoplasma mycoides Subsp. mycoides

et al. 2013

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“…The residues A, D, and H were also identified as glucopyranoses: the former two are terminal units in α-anomeric configuration, and the latter is a 1,6-linked β-anomeric unit. The C1 signals of C and E in the region of δ 106–108 are typical for the furanose ring and thus indicate β-galactofuranose. − By contrast, residue F was identified as α-mannopyranose . NMR data for some minor units are insufficient to make exact assignments.…”

Section: Resultsmentioning

confidence: 99%

Cell Wall Components of Leptosphaeria maculans Enhance Resistance of Brassica napus

Kim¹,

Šašek

Burketová

et al. 2013

J. Agric. Food Chem.

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Preparations with elicitation activity were obtained from the mycelium of Leptosphaeria maculans , a fungal pathogen of oilseed rape (Brassica napus). Crude delipidated and deproteinized extract from fungal cell walls induced expression of pathogenesis related gene 1 (PR1), hydrogen peroxide accumulation, and enhanced resistance of B. napus plants toward infection by L. maculans. Elicitation activity significantly decreased after treatment of a crude extract with α- or β-glucanase. Monosaccharide composition analysis of a crude extract purified by ion-exchange chromatography revealed glucose (∼58 mol %), mannose (∼22 mol %), and galactose (∼18 mol %) as the major sugars. FT-IR and NMR spectra confirmed the presence of both carbohydrate and polypeptide components in the purified product. Correlation NMR experiments defined trisaccharide bound to O-3 of serine residue α-D-Glcp-(1→2)-β-D-Galf-(1→6)-α-D-Manp-(1→3)-L-Ser. Terminal α-D-Glcp and (1→6)-β-D-glucan were also detected. The obtained results strongly support the conclusion that these carbohydrates induce defense response in B. napus plants.

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“…In correspondence, six residues were identified by COSY and HSQ spectrum. Their anomeric carbons and protons were also observed in HSQC (Figure 2 The signals of B (5.1/106.7), C (5.03/106.9), and F (4.9/107.4) represented three differ galactofuranose residues, which were determined by unusual low-field shifts of the a meric carbon signals at about 107 ppm [19]. Moreover, the COSY spectrum ( Combined with a methylation an ysis, F was deduced to be a terminal β-D-Galf residue.…”

Section: Nmr Analysismentioning

confidence: 86%

“…Their anomeric carbons and protons were also observed in HSQC (Figure 2b). The signals of B (5.1/106.7), C (5.03/106.9), and F (4.9/107.4) represented three different galactofuranose residues, which were determined by unusual low-field shifts of the anomeric carbon signals at about 107 ppm [19]. Moreover, the COSY spectrum (Figure 2c) revealed the relevance of H1/H2 of units B and C at 5.1/4.04 and 5.03/4.01, respectively.…”

Section: Nmr Analysismentioning

confidence: 99%

A New Galactoglucomannan from the Mycelium of the Medicinal Parasitic Fungus Cordyceps cicadae and Its Immunomodulatory Activity In Vitro and In Vivo

2023

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A new galactoglucomannan (C-0-1) was purified from the medicinal parasitic fungus of Cordyceps cicadae using an anion-exchange column and gel permeation column. The results of high-performance liquid chromatography and high-performance gel permeation chromatography indicated that C-0-1 consists of galactose, glucose, and mannose in a ratio of 5:1:4 and has a molecular weight of 23.3 kDa. The combined structural elucidation analysis methods including partial acid hydrolysis, methylation analysis, and NMR experiments revealed that C-0-1 was a comb-like polysaccharide with a core structure including (1→2)-α-D-Manp residues in the backbone and branches at O-6 of the main chain. (1→4)-α-D-Glcp, (1→2)-β-D-Galf, (1→2,6)-β-D-Galf, and terminal β-Galf were located at the side chains. An in vitro experiment using RAW 264.7 cells indicated that C-0-1 exhibits good immunomodulatory activity by enhancing inducible nitric oxide synthase secretion and the production of some major inflammatory cytokines. On inhibiting the cytokine production using anti-pattern recognition receptors antibodies, it was revealed that the activation of macrophages is mainly carried out by C-0-1 through the mannose receptor. Toll-like receptor 4 and Toll-like receptor 2 were also involved in this identification process. An in vivo experiment on immunosuppressive mice treated with cyclophosphamide indicated that C-0-1 improves the secretion of serum-related cytokines (IFN-γ, TNF-α, IL-2, IL-4, and IL-10) and affects the balance of T helper cells Th1/Th2. Given the structural and bioactivity similarity between Cordyceps cicadae and Cordyceps sinensis, we can conclude that Cordyceps cicadae could be used as an important medicinal fungus like Cordyceps sinensis.

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(1 → 2) and (1 → 6)-linked β-d-galactofuranan of microalga Myrmecia biatorellae, symbiotic partner of Lobaria linita

Cited by 12 publications

References 36 publications

Characterization of Free Exopolysaccharides Secreted by Mycoplasma mycoides Subsp. mycoides

Characterization of Free Exopolysaccharides Secreted by Mycoplasma mycoides Subsp. mycoides

Cell Wall Components of Leptosphaeria maculans Enhance Resistance of Brassica napus

A New Galactoglucomannan from the Mycelium of the Medicinal Parasitic Fungus Cordyceps cicadae and Its Immunomodulatory Activity In Vitro and In Vivo

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