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Hugo Scheer - One of the best experts on this subject based on the ideXlab platform.
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Energy Transfer In the Core Pigments of Phycoblllsomes from Mastlgocladus laminosus As Studied by Temperature-Dependent Hole Burning
2015Co-Authors: Alessaadro Feis *gt, Lothar Gottschalk, Hugo ScheerAbstract:Persistent optical hole burning has been performed in the allophycocyanin band of phycobilisomes of Mastigocladus laminosus. The homogeneous transition line width has been obtained by a careful analysis of the hole-burning data. The dependence of the line width on temperature has been measured in the range 1.5-4.2 K. A lifetime-limited value of 1.08 A 0.21 GHz is obtained as a result of linear back extrapolation to T = 0 K. It corresponds to an energy transfer time of 147 f IS ps from allophycocyanin to the terminal emitters of the phycobilisome core
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resonance enhanced cars spectroscopy of biliproteins influence of aggregation and linker proteins on chromophore structure in allophycocyanin Mastigocladus laminosus
Photochemistry and Photobiology, 2008Co-Authors: Siegfried Schneider, Kaihong Zhao, C. J. Prenzel, G. Brehm, Lothar Gottschalk, Hugo ScheerAbstract:— Resonance-enhanced coherent anti-Stokes Raman spectra (CARS) are reported for monomers and for trimers with and without linker proteins of allophycocyanin isolated from Mastigocladus laminosus. The CARS spectrum of the monomer is independent of the presence of linker proteins and is very similar to that of phycocyanin monomers indicating that the equivalent chromophores exhibit like structures in both biliproteins. Large differences are, however, observed between the spectra of phycocyanin trimers and those of allophycocyanin trimers with or without linker proteins (Lc8,9). The observed differences between monomer and trimer spectra are consistent with a change of the α-chromophore-protein arrangement upon aggregation without linker. If linker proteins are present in the trimer, then additional geometry changes of the β-chromophores are induced; these could relate to a transition from the 15Z-anti to 15Z-syn conformation.
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characterization of phycoviolobilin phycoerythrocyanin alpha 84 cystein lyase isomerizing from Mastigocladus laminosus
FEBS Journal, 2002Co-Authors: Kaihong Zhao, Ming Zhou, Max Storf, Brigitte Strohmann, Lu Wang, Claudia Bubenzer, Hugo ScheerAbstract:Cofactor requirements and enzyme kinetics have been studied of the novel, dual-action enzyme, the isomerizing phycoviolobilin phycoerythrocyanin-alpha84-cystein-lyase(PVB-PEC-lyase) from Mastigocladus laminosus, which catalyses both the covalent attachment of phycocyanobilin to PecA, the apo-alpha-subunit of phycoerythrocyanin, and its isomerization to phycoviolobilin. Thiols and the divalent metals, Mg2+ or Mn2+, were required, and the reaction was aided by the detergent, Triton X-100. Phosphate buffer inhibits precipitation of the proteins present in the reconstitution mixture, but at the same time binds the required metal. Kinetic constants were obtained for both substrates, the chromophore (Km = 12-16 micro m, depending on [PecA], kcat approximately 1.2 x 10-4.s-1) and the apoprotein (Km = 2.4 micro m at 14 micro m PCB, kcat = 0.8 x 10-4.s-1). The kinetic analysis indicated that the reconstitution reaction proceeds by a sequential mechanism. By a combination of untagged and His-tagged subunits, evidence was obtained for a complex formation between PecE and PecF (subunits of PVB-PEC-lyase), and by experiments with single subunits for the prevalent function of PecE in binding and PecF in isomerizing the chromophore.
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novel activity of a phycobiliprotein lyase both the attachment of phycocyanobilin and the isomerization to phycoviolobilin are catalyzed by the proteins pece and pecf encoded by the phycoerythrocyanin operon
FEBS Letters, 2000Co-Authors: Kaihong Zhao, Axel Parbel, Minggang Deng, Min Zheng, Ming Zhou, Max Storf, M Meyer, Brigitte Strohmann, Hugo ScheerAbstract:Abstract The structure of phycoviolobilin, the photoactive chromophore of α-phycoerythrocyanin, is incompatible with a chromophore ligation to the apoprotein via SH-addition (cysteine) to a Δ3,31-double bond of the phycobilin. The two putative phycoerythrocyanin lyase genes of Mastigocladus laminosus, pecE and pecF, were overexpressed in Escherichia coli. Their action has been studied on the addition reaction of phycocyanobilin to apo-α-phycoerythrocyanin (PecA). In the absence of the components of α-PEC-phycoviolobilin lyase PecE and PecF, or in the presence of only one of them, phycocyanobilin binds covalently to PecA forming a fluorescent chromoprotein with a red-shifted absorption (λmax=641 nm) and low photoactivity (
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model for the phycobilisome rod with interlocking disks based on domain weighted linker polypeptide sequence homologies of Mastigocladus laminosus
International Journal of Photoenergy, 2000Co-Authors: Axel Parbel, Hugo ScheerAbstract:The 8 linker-polypeptides from the cyanobacterium Mastigocladus laminosus were examined by comparative amino-acid sequence analysis for the predicted domain structure reported in the literatur (Glauser 1991, Esteban 1993) in detail using split sequences for the rod, rod-core and for the repeats from the core-membrane linker-polypeptide (Lcm127.6). This analysis gives two distinct domains, where domain 1 (∼ 22 kDa, identity between 31 and 70%) is present in the N-terminal two thirds of the class II linkers (∼ 30 kDa) and in the repeats of the Lcm127.6, and domain 2 (∼ 10 kDa, identity between 28 and 41%) in the C-terminal part of the class II rod linkers (Lr31.5 and Lr32.5) and in the two capping linkers (Lc7.7 and Lr8.2). Based on these data, X-ray structure analysis from phycobiliproteins and proteolysis experiments, an interlocking model for the phycobilisome rod organization is proposed, with linkers protruding from one phycobilisome disk into the neighbouring one.
Beatriz Díez - One of the best experts on this subject based on the ideXlab platform.
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Active Crossfire Between Cyanobacteria and Cyanophages in Phototrophic Mat Communities Within Hot Springs.
Frontiers in Microbiology, 2018Co-Authors: Sergio Guajardo-leiva, Oscar Salgado, Fabián Pinto, Carlos Pedrós-alió, Beatriz DíezAbstract:Cyanophages are viruses with a wide distribution in aquatic ecosystems, that specifically infect Cyanobacteria. These viruses can be readily isolated from marine and fresh waters environments; however, their presence in cosmopolitan thermophilic phototrophic mats remains largely unknown. This study investigates the morphological diversity (TEM), taxonomic composition (metagenomics), and active infectivity (metatranscriptomics) of viral communities over a thermal gradient in hot spring phototrophic mats from Northern Patagonia (Chile). The mats were dominated (up to 53%) by cosmopolitan thermophilic filamentous true-branching cyanobacteria from the genus Mastigocladus, the associated viral community was predominantly composed of Caudovirales (70%), with most of the active infections driven by cyanophages (up to 90% of Caudovirales transcripts). Metagenomic assembly lead to the first full genome description of a T7-like Thermophilic Cyanophage recovered form a hot spring (Porcelana Hot Spring, Chile), with a temperature of 58oC (TC-CHP58). This could potentially represent a world-wide thermophilic lineage of podoviruses that infect cyanobacteria. In the hot spring, TC-CHP58 was active over a temperature gradient from 48 to 66oC, showing a high population variability represented by 1979 Single Nucleotide Variants (SNVs). TC-CHP58 was associated to the Mastigocladus sp. by CRISPR spacers. Marked differences in metagenomic CRISPR loci number and spacers diversity, as well as SNVs, in the TC-CHP58 proto-spacers at different temperatures, reinforce the theory of co-evolution between natural virus populations and cyanobacterial hosts. Considering the importance of cyanobacteria in hot spring biogeochemical cycles, the description of this new cyanopodovirus lineage may have global implications for the functioning of these extreme ecosystems.
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Image_7_Diurnal Changes in Active Carbon and Nitrogen Pathways Along the Temperature Gradient in Porcelana Hot Spring Microbial Mat.JPEG
2018Co-Authors: María E. Alcamán-arias, Carlos Pedrós-alió, Javier Tamames, Camila Fernandez, Monica Vasquez, Danilo Pérez-pantoja, Beatriz DíezAbstract:Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin–Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.
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Table_1_Diurnal Changes in Active Carbon and Nitrogen Pathways Along the Temperature Gradient in Porcelana Hot Spring Microbial Mat.XLSX
2018Co-Authors: María E. Alcamán-arias, Carlos Pedrós-alió, Javier Tamames, Camila Fernandez, Monica Vasquez, Danilo Pérez-pantoja, Beatriz DíezAbstract:Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin–Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.
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Data_Sheet_1_Active Crossfire Between Cyanobacteria and Cyanophages in Phototrophic Mat Communities Within Hot Springs.PDF
2018Co-Authors: Sergio Guajardo-leiva, Oscar Salgado, Fabián Pinto, Carlos Pedrós-alió, Beatriz DíezAbstract:Cyanophages are viruses with a wide distribution in aquatic ecosystems, that specifically infect Cyanobacteria. These viruses can be readily isolated from marine and fresh waters environments; however, their presence in cosmopolitan thermophilic phototrophic mats remains largely unknown. This study investigates the morphological diversity (TEM), taxonomic composition (metagenomics), and active infectivity (metatranscriptomics) of viral communities over a thermal gradient in hot spring phototrophic mats from Northern Patagonia (Chile). The mats were dominated (up to 53%) by cosmopolitan thermophilic filamentous true-branching cyanobacteria from the genus Mastigocladus, the associated viral community was predominantly composed of Caudovirales (70%), with most of the active infections driven by cyanophages (up to 90% of Caudovirales transcripts). Metagenomic assembly lead to the first full genome description of a T7-like Thermophilic Cyanophage recovered from a hot spring (Porcelana Hot Spring, Chile), with a temperature of 58°C (TC-CHP58). This could potentially represent a world-wide thermophilic lineage of podoviruses that infect cyanobacteria. In the hot spring, TC-CHP58 was active over a temperature gradient from 48 to 66°C, showing a high population variability represented by 1979 single nucleotide variants (SNVs). TC-CHP58 was associated to the Mastigocladus spp. by CRISPR spacers. Marked differences in metagenomic CRISPR loci number and spacers diversity, as well as SNVs, in the TC-CHP58 proto-spacers at different temperatures, reinforce the theory of co-evolution between natural virus populations and cyanobacterial hosts. Considering the importance of cyanobacteria in hot spring biogeochemical cycles, the description of this new cyanopodovirus lineage may have global implications for the functioning of these extreme ecosystems.
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physiological and gene expression responses to nitrogen regimes and temperatures in Mastigocladus sp strain chp1 a predominant thermotolerant cyanobacterium of hot springs
Systematic and Applied Microbiology, 2017Co-Authors: Estrella M Alcaman, Monica Vasquez, Jaime Alcorta, Birgitta Bergman, Martin F Polz, Beatriz DíezAbstract:Cyanobacteria are widely distributed primary producers with significant implications for the global biogeochemical cycles of carbon and nitrogen. Diazotrophic cyanobacteria of subsection V (Order Stigonematales) are particularly ubiquitous in photoautotrophic microbial mats of hot springs. The Stigonematal cyanobacterium strain CHP1 isolated from the Porcelana hot spring (Chile) was one of the major contributors of the new nitrogen through nitrogen fixation. Further morphological and genetic characterization verified that the strain CHP1 belongs to Stigonematales, and it formed a separate clade together with other thermophiles of the genera Fischerella and Mastigocladus. Strain CHP1 fixed maximum N2 in the light, independent of the temperature range. At 50°C nifH gene transcripts showed high expression during the light period, whereas the nifH gene expression at 45°C was arrhythmic. The strain displayed a high affinity for nitrate and a low tolerance for high ammonium concentrations, whereas the narB and glnA genes showed higher expression in light and at the beginning of the dark phase. It is proposed that Mastigocladus sp. strain CHP1 would represent a good model for the study of subsection V thermophilic cyanobacteria, and for understanding the adaptations of these photoautotrophic organisms inhabiting microbial mats in hot springs globally.
Lothar Gottschalk - One of the best experts on this subject based on the ideXlab platform.
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Energy Transfer In the Core Pigments of Phycoblllsomes from Mastlgocladus laminosus As Studied by Temperature-Dependent Hole Burning
2015Co-Authors: Alessaadro Feis *gt, Lothar Gottschalk, Hugo ScheerAbstract:Persistent optical hole burning has been performed in the allophycocyanin band of phycobilisomes of Mastigocladus laminosus. The homogeneous transition line width has been obtained by a careful analysis of the hole-burning data. The dependence of the line width on temperature has been measured in the range 1.5-4.2 K. A lifetime-limited value of 1.08 A 0.21 GHz is obtained as a result of linear back extrapolation to T = 0 K. It corresponds to an energy transfer time of 147 f IS ps from allophycocyanin to the terminal emitters of the phycobilisome core
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resonance enhanced cars spectroscopy of biliproteins influence of aggregation and linker proteins on chromophore structure in allophycocyanin Mastigocladus laminosus
Photochemistry and Photobiology, 2008Co-Authors: Siegfried Schneider, Kaihong Zhao, C. J. Prenzel, G. Brehm, Lothar Gottschalk, Hugo ScheerAbstract:— Resonance-enhanced coherent anti-Stokes Raman spectra (CARS) are reported for monomers and for trimers with and without linker proteins of allophycocyanin isolated from Mastigocladus laminosus. The CARS spectrum of the monomer is independent of the presence of linker proteins and is very similar to that of phycocyanin monomers indicating that the equivalent chromophores exhibit like structures in both biliproteins. Large differences are, however, observed between the spectra of phycocyanin trimers and those of allophycocyanin trimers with or without linker proteins (Lc8,9). The observed differences between monomer and trimer spectra are consistent with a change of the α-chromophore-protein arrangement upon aggregation without linker. If linker proteins are present in the trimer, then additional geometry changes of the β-chromophores are induced; these could relate to a transition from the 15Z-anti to 15Z-syn conformation.
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RECONSTITUTION OF ALLOPHYCOCYANIN FROM Mastigocladus laminosus WITH ISOLATED LINKER POLYPEPTIDE
Photochemistry and Photobiology, 1993Co-Authors: Lothar Gottschalk, Friedrich Lottspeich, Hugo ScheerAbstract:The core linker polypeptide Lc 8.9 was isolated from Mastigocladus laminosus and purified on a preparative scale. A method for the reconstitution of allophycocyanin (AP)—linker complexes from isolated polypeptides was developed. The complex (αAP(βAP)3 Lc 8.9 was reconstituted and compared to (αAPβAP) and (αAPβAP)3 by sucrose density gradient ultracentrifugation, absorption, fluorescence emission and circular dichroism spectroscopy. Differences in the spectra of reconstituted and of directly isolated AP complexes are discussed.
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energy transfer in the core pigments of phycobilisomes from Mastigocladus laminosus as studied by temperature dependent hole burning
The Journal of Physical Chemistry, 1992Co-Authors: Alessandro Feis, Lothar Gottschalk, J Friedrich, Hugo ScheerAbstract:Persistent optical hole burning has been performed in the allophycocyanin band of phycobilisomes of Mastigocladus laminosus. The homogeneous transition line width has been obtained by a careful analysis of the hole-burning data. The dependence of the line width on temperature has been measured in the range 1.5-4.2 K. A lifetime-limited value of 1.08 A 0.21 GHz is obtained as a result of linear back extrapolation to T = 0 K. It corresponds to an energy transfer time of 147 f IS ps from allophycocyanin to the terminal emitters of the phycobilisome core.
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origin of the red shifted absorption in phycocyanin 632 from Mastigocladus laminosus
Photochemistry and Photobiology, 1991Co-Authors: Lothar Gottschalk, Roland A Fischer, F Lottspeich, Hugo ScheerAbstract:A phycocyanin (PC) with γmax= 632 nm (PC632) was isolated from extracts of the cyanobacterium Mastigocladus laminosus. The complex contained three polypeptides migrating in SDS-PAGE around 22 kDa. The N-termini of the three polypeptides are identical. They are homologous to rod-core linker polypeptides from this and another cyanobacterium and are identical to one of them. Reconstitution of PC (γmax=614–620 nm) with the 22 kDa polypeptide produced again the red-shifted PC632. Phycobilisomes isolated at pH 6 or 7 contain, if any, only traces of 22 kDa polypeptides. Origin and functions of the polypeptides are discussed, they are most likely proteolytic fragments of allophycocyanin-PC rod-core linkers that contain the PC-binding domain.
Maria E Alcamanarias - One of the best experts on this subject based on the ideXlab platform.
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diurnal changes in active carbon and nitrogen pathways along the temperature gradient in porcelana hot spring microbial mat
Frontiers in Microbiology, 2018Co-Authors: Maria E Alcamanarias, Carlos Pedrosalio, Javier Tamames, Camila Fernandez, Danilo Perezpantoja, Monica VasquezAbstract:Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin-Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.
Vincent Gloaguen - One of the best experts on this subject based on the ideXlab platform.
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proprietes anti inflammatoires du polysaccharide capsulaire produit par la cyanobacterie thermophile Mastigocladus laminosus
La Presse thermale et climatique, 2008Co-Authors: Vincent Gloaguen, Pierre KrauszAbstract:Les cyanobacteries constituent un groupe important de micro organismes producteurs de molecules biologiquement actives qui presentent un interet therapeutique. Elles forment des tapis qui sont utilises empiriquement pour leurs proprietes pharmacodynamiques par les medecins des stations thermales. C'est le cas a Neris-les-Bains (chaine thermale d'Auvergne, France) ou Mastigocladus laminosus, une cyanobacterie thermophile, est utilisee melangee a de l'argile afin de soigner la polyarthrite rhumatoide et les douleurs rhumatismales traumatiques. Ces tapis de cyanobacteries produisent un polysaccharide exocellulaire dont la structure a ete caracterisee chimiquement. Un effet anti-inflammatoire important et dependant des doses administrees a ete observe suite a l'application locale de ce polysaccharide sur l'oreille de souris presentant un oedeme provoque par de l'huile de croton. L'application d'un hydrolysat partiel du polymere, compose uniquement d'oligosaccharides, a reduit l'oedeme de facon similaire au polymere, indiquant que l'activite anti-inflammatoire est associee a la fraction polysaccharidique.
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Propriétés inflammatoires du polysaccharide capsulaire produit par la cyanobactérie thermophile Mastigocladus laminosus.
Presse thermale et climatique, 2008Co-Authors: Vincent Gloaguen, Pierre KrauszAbstract:Les cyanobactéries constituent un groupe important de micro organismes producteurs de molécules biologiquement actives qui présentent un intérêt thérapeutique. Elles forment des tapis qui sont utilisés empiriquement pour leurs propriétés pharmacodynamiques par les médecins des stations thermales. C'est le cas à Néris-les-Bains (chaîne thermale d'Auvergne, France) où Mastigocladus laminosus, une cyanobactérie thermophile, est utilisée mélangée à de l'argile afin de soigner la polyarthrite rhumatoïde et les douleurs rhumatismales traumatiques. Ces tapis de cyanobactéries produisent un polysaccharide exocellulaire dont la structure a été caractérisée chimiquement. Un effet anti-inflammatoire important et dépendant des doses administrées a été observé suite à l'application locale de ce polysaccharide sur l'oreille de souris présentant un œdème provoqué par de l'huile de croton. L'application d'un hydrolysat partiel du polymère, composé uniquement d'oligosaccharides, a réduit l'œdème de façon similaire au polymère, indiquant que l'activité anti-inflammatoire est associée à la fraction polysaccharidique.
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bioactive capsular polysaccharide from the thermophilic cyanophyte cyanobacterium Mastigocladus laminosus cytotoxic properties
Planta Medica, 2007Co-Authors: Vincent Gloaguen, Henri Morvan, Lucien Hoffmann, Odile Sainte Catherine, Michel Kraemer, Pierre KrauszAbstract:The capsular polysaccharide produced by the thermophilic blue green alga/cyanobacterium Mastigocladus laminosus was tested for its cytotoxic activity against the A431 human epidermoid carcinoma cell line. This polysaccharide inhibited the proliferation of A431 cells in a dose-dependent manner with an IC (50) value of 50 microg mL (-1). In addition, this polysaccharide strongly inhibited A431 cell migration and invasion. Preliminary experiments showing that secretion of metalloproteinases MMP2 and MMP9 by A431 tumour cells was inhibited by this polysaccharide suggest that this mechanism of action could play a role in its anti-migration and anti-invasive properties. Acid hydrolysis of the polysaccharide produced specific oligosaccharides which conserved - at similar concentrations - their cytotoxic, anti-migration and anti-invasion properties; in this case, the mechanism of action was nevertheless uncorrelated to the decrease of metalloproteinase expression.
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bioactive capsular polysaccharide from the thermophilic Mastigocladus laminosus cyanophyceae cyanobacteria demonstration of anti inflammatory properties
Algological Studies Archiv für Hydrobiologie Supplement Volumes, 2003Co-Authors: Vincent Gloaguen, Henri Morvan, Nancy Garbacki, Daniel Petit, Lucien HoffmannAbstract:The anti-inflammatory, antimicrobial and cytotoxic activities of the capsular polymer produced by the thermophilic blue-green alga Mastigocladus laminosus were tested. Used at concentrations ranging fom 10 -5 to 1 mg ml -1 , the extracts didn't show an inhibition of human cell activity or a significant effect on the growth of Gram-negative and Gram-positive bacteria, and of a yeast strain. However, a very significant and dose-dependent anti-inflammatory effect was obtained when the extracts were topically applied on croton oil-induced oedema in mice ear skin. The application of a partial hydrolysate of the polymer only formed by oligosaccharides with degrees of polymerisation ranging from 2 to 5 reduced the oedema in a similar way as the polymer, indicating that the anti-inflammatory activity is associated with the polysaccharidic fraction.
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capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus structural study of an undecasaccharide obtained by lithium degradation
FEBS Journal, 1999Co-Authors: Vincent Gloaguen, Henri Morvan, Lucien Hoffmann, Yves Plancke, Jeanmichel Wieruszeski, Guy Lippens, Gerard StreckerAbstract:The capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus has been subjected to a specific degradation with lithium in ethylenediamine. The released undecasaccharide attached to one unit of tetrahydroxycyclopentanecarboxylic acid has been characterized by a combination of 2D nuclear magnetic resonance spectroscopy, mass spectrometry, monosaccharidic composition and linkage analyses. From the overlap of the structure of this oligosaccharide with previously identified di-, tri- and pentasaccharides released by mild acid hydrolysis, the capsular polysaccharide was deduced to have a pentadecasaccharide repeating unit with the following structure: