Development of a scalable recombinant system for cyclic beta-1,2-glucans production.

Background: Cyclic β-1,2-glucans (CβG) are bacterial cyclic homopolysaccharides with interesting biotechnological applications. These ring-shaped molecules have a hydrophilic surface that confers high solubility and a hydrophobic cavity able to include poorly soluble molecules. Several studies demonstrate that CβG and many derivatives can be applied in drug solubilization and stabilization, enantiomer separation, catalysis, synthesis of nanomaterials and even as immunomodulators, suggesting these molecules have great potential for their industrial and commercial exploitation.

Hallmarks of the relationship between host and sulfated glycoconjugates along the course of Chagas disease.

American Trypanosomiasis or Chagas disease (ChD), a major problem that is still endemic in large areas of Latin America, is caused by . This agent holds a major antigen, cruzipain (Cz). Its C-terminal domain (C-T) is retained in the glycoprotein mature form and bears several post-translational modifications.

Insights into the xylan degradation system of Cellulomonas sp. B6: biochemical characterization of rCsXyn10A and rCsAbf62A.

Valorization of the hemicellulose fraction of plant biomass is crucial for the sustainability of lignocellulosic biorefineries. The Cellulomonas genus comprises Gram-positive Actinobacteria that degrade cellulose and other polysaccharides by secreting a complex array of enzymes. In this work, we studied the specificity and synergy of two enzymes, CsXyn10A and CsAbf62A, which were identified as highly abundant in the extracellular proteome of Cellulomonas sp.

Cruzipain Sulfotopes-Specific Antibodies Generate Cardiac Tissue Abnormalities and Favor Infection in the BALB/c Mice Model of Experimental Chagas Disease.

cruzipain (Cz) bears a C-terminal domain (C-T) that contains sulfated epitopes "sulfotopes" (GlcNAc6S) on its unique N-glycosylation site. The effects of exposure to GlcNAc6S on heart tissue ultrastructure, immune responses, and along the outcome of infection by , were evaluated in a murine experimental model, BALB/c, using three independent strategies. First, mice were pre-exposed to C-T by immunization.

PsAA9A, a C1-specific AA9 lytic polysaccharide monooxygenase from the white-rot basidiomycete Pycnoporus sanguineus.

Woody biomass represents an important source of carbon on earth, and its global recycling is highly dependent on Agaricomycetes fungi. White-rot Basidiomycetes are a very important group in this regard, as they possess a large and diverse enzymatic repertoire for biomass decomposition. Among these enzymes, the recently discovered lytic polysaccharide monooxygenases (LPMOs) have revolutionized biomass processing with their novel oxidative mechanism of action.

Immunostimulation by S-layer proteins with distinct glycosylation patterns requires different lectin partners.

S-layer (glyco)-proteins (SLPs) form a nanostructured envelope that covers the surface of different prokaryotes and show immunomodulatory activity. Previously, we have demonstrated that the S-layer glycoprotein from probiotic CIDCA 8348 (SLP-8348) is recognized by Mincle (macrophage inducible C-type lectin receptor), and its adjuvanticity depends on the integrity of its glycans. However, the glycan's structure has not been described so far.

Structural characterization and metal biosorptive activity of the major polysaccharide produced by Pseudomonas veronii 2E.

Pseudomonas veronii 2E, an autochthonous bacterium isolated from sediments associated to a high-polluted watershed, produces a complex matrix of exopolymers with carbohydrates as main components. In this work, four polysaccharides were isolated from the extracellular material. The major acidic polysaccharide named EPO2, was purified and its structure was elucidated using Matrix-assisted laser desorption/ionization and Electrospray ionization mass spectrometry, Infrared spectroscopy, Nuclear magnetic resonance spectroscopy and chemical treatments.

Strawberry fatty acyl glycosides enhance disease protection, have antibiotic activity and stimulate plant growth.

An increasing interest in the development of products of natural origin for crop disease and pest control has emerged in the last decade. Here we introduce a new family of strawberry acyl glycosides (SAGs) formed by a trisaccharide (GalNAc-GalNAc-Glc) and a monounsaturated fatty acid of 6 to 12 carbon atoms linked to the glucose unit. Application of SAGs to Arabidopsis thaliana (hereafter Arabidopsis) plants triggered a transient oxidative burst, callose deposition and defense gene expression, accompanied by increased protection against two phytopathogens, Pseudomonas viridiflava and Botrytis cinerea.

Infrared spectroscopy with multivariate analysis to interrogate the interaction of whole cells and secreted soluble exopolimeric substances of Pseudomonas veronii 2E with Cd(II), Cu(II) and Zn(II).

Extracellular polymeric substances (EPS) are bacterial products associated to cell wall or secreted to the liquid media that form the framework of microbial mats. These EPS contain functional groups as carboxyl, amino, hydroxyl, phosphate and sulfhydryl, able to interact with cations. Thus, EPS may be considered natural detoxifying compounds of metal polluted waters and wastewaters.

Tamoxifen acts on Trypanosoma cruzi sphingolipid pathway triggering an apoptotic death process.

This study shows the effects of tamoxifen, a known estrogen receptor antagonist used in the treatment of breast cancer, on the sphingolipid pathway of Trypanosoma cruzi, searching for potential chemotherapeutic targets. A dose-dependent epimastigote growth inhibition at increasing concentration of tamoxifen was determined. In blood trypomastigotes, treatment with 10 μM showed 90% lysis, while 86% inhibition of intracellular amastigote development was obtained using 50 μM.

Bordetella bronchiseptica Glycosyltransferase Core Mutants Trigger Changes in Lipid A Structure.

Bordetella bronchiseptica, known to infect animals and rarely humans, expresses a lipopolysaccharide that plays an essential role in host interactions, being critical for early clearance of the bacteria. On a B. bronchiseptica 9.

Heat-stress triggers MAPK crosstalk to turn on the hyperosmotic response pathway.

Cells make decisions based on a combination of external and internal signals. In yeast, the high osmolarity response (HOG) is a mitogen-activated protein kinase (MAPK) pathway that responds to a variety of stimuli, and it is central to the general stress response. Here we studied the effect of heat-stress (HS) on HOG.

Effect of tamoxifen on the sphingolipid biosynthetic pathway in the different intraerythrocytic stages of the apicomplexa Plasmodium falciparum.

Parasites of the genus Plasmodium responsible for Malaria are obligate intracellular pathogens residing in mammalian red blood cells, hepatocytes, or mosquito midgut epithelial cells. Regarding that detailed knowledge on the sphingolipid biosynthetic pathway of the apicomplexan protozoan parasites is scarce, different stages of Plasmodium falciparum were treated with tamoxifen in order to evaluate the effects of this drug on the glycosphingolipid biosynthesis. Thin layer chromatography, High performance reverse phase chromatography and UV-MALDI-TOF mass spectrometry were the tools used for the analysis.

RomA, A Periplasmic Protein Involved in the Synthesis of the Lipopolysaccharide, Tunes Down the Inflammatory Response Triggered by Brucella.

Brucellaceae are stealthy pathogens with the ability to survive and replicate in the host in the context of a strong immune response. This capacity relies on several virulence factors that are able to modulate the immune system and in their structural components that have low proinflammatory activities. Lipopolysaccharide (LPS), the main component of the outer membrane, is a central virulence factor of Brucella, and it has been well established that it induces a low inflammatory response.

Trypanosoma cruzi serinecarboxipeptidase is a sulfated glycoprotein and a minor antigen in human Chagas disease infection.

In this work, the presence of sulfated N-glycans was studied in a high-mannose-type glycoprotein of Trypanosoma cruzi with serinecarboxipeptidase (TcSCP) activity. The immune cross-reactivity between purified SCP and Cruzipain (Cz) was evidenced using rabbit sera specific for both glycoproteins. Taking advantage that SCP co-purifies with Cz from Concanavalin-A affinity columns, the Cz-SCP mixture was desulfated, ascribing the cross-reactivity to the presence of sulfate groups in both molecules.

New Features in the Lipid A Structure of Brucella suis and Brucella abortus Lipopolysaccharide.

Brucellaceae are Gram-negative bacteria that cause brucellosis, one of the most distributed worldwide zoonosis, transmitted to humans by contact with either infected animals or their products. The lipopolysaccharide exposed on the cell surface has been intensively studied and is considered a major virulence factor of Brucella. In the last years, structural studies allowed the determination of new structures in the core oligosaccharide and the O-antigen of this lipopolysaccharide.

A glycoproteomic approach reveals that the S-layer glycoprotein of Lactobacillus kefiri CIDCA 83111 is O- and N-glycosylated.

Unlabelled: In Gram-positive bacteria, such as lactic acid bacteria, general glycosylation systems have not been documented so far. The aim of this work was to characterize in detail the glycosylation of the S-layer protein of Lactobacillus kefiri CIDCA 83111. A reductive β-elimination treatment followed by anion exchange high performance liquid chromatography analysis was useful to characterize the O-glycosidic structures.

High molecular weight components containing N-linked oligosaccharides of Ascaris suum extract inhibit the dendritic cells activation through DC-SIGN and MR.

Helminths, as well as their secretory/excretory products, induce a tolerogenic immune microenvironment. High molecular weight components (PI) from Ascaris suum extract down-modulate the immune response against ovalbumin (OVA). The PI exerts direct effect on dendritic cells (DCs) independent of TLR 2, 4 and MyD88 molecule and, thus, decreases the T lymphocytes response.

Modifications of Bordetella bronchiseptica core lipopolysaccharide influence immune response without affecting protective activity.

Bordetella bronchiseptica produces respiratory disease primarily in mammals including humans. Although a considerably amount of research has been generated regarding lipopolysaccharide (LPS) role during infection and stimulating innate and adaptive immune response, mechanisms involved in LPS synthesis are still unknown. In this context we searched in B.

Deletion of pilA, a Minor Pilin-Like Gene, from Xanthomonas citri subsp. citri Influences Bacterial Physiology and Pathogenesis.

Type IV pili (Tfp) are widely distributed adhesins of bacterial surfaces. In plant pathogenic bacteria, Tfp are involved in host colonization and pathogenesis. Xanthomonas citri subsp.

Effects of chlorate on the sulfation process of Trypanosoma cruzi glycoconjugates. Implication of parasite sulfates in cellular invasion.

Sulfation, a post-translational modification which plays a key role in various biological processes, is inhibited by competition with chlorate. In Trypanosoma cruzi, the agent of Chagas' disease, sulfated structures have been described as part of glycolipids and we have reported sulfated high-mannose type oligosaccharides in the C-T domain of the cruzipain (Cz) glycoprotein. However, sulfation pathways have not been described yet in this parasite.

A rhomboid protease gene deletion affects a novel oligosaccharide N-linked to the S-layer glycoprotein of Haloferax volcanii.

Rhomboid proteases occur in all domains of life; however, their physiological role is not completely understood, and nothing is known of the biology of these enzymes in Archaea. One of the two rhomboid homologs of Haloferax volcanii (RhoII) is fused to a zinc finger domain. Chromosomal deletion of rhoII was successful, indicating that this gene is not essential for this organism; however, the mutant strain (MIG1) showed reduced motility and increased sensitivity to novobiocin.

Solanesyl diphosphate synthase, an enzyme of the ubiquinone synthetic pathway, is required throughout the life cycle of Trypanosoma brucei.

Ubiquinone 9 (UQ9), the expected product of the long-chain solanesyl diphosphate synthase of Trypanosoma brucei (TbSPPS), has a central role in reoxidation of reducing equivalents in the mitochondrion of T. brucei. The ablation of TbSPPS gene expression by RNA interference increased the generation of reactive oxygen species and reduced cell growth and oxygen consumption.

Pheromone-induced morphogenesis improves osmoadaptation capacity by activating the HOG MAPK pathway.

Environmental and internal conditions expose cells to a multiplicity of stimuli whose consequences are difficult to predict. We investigate the response to mating pheromone of yeast cells adapted to high osmolarity. Events downstream of pheromone binding involve two mitogen-activated protein kinase (MAPK) cascades: the pheromone response (PR) and the cell wall integrity (CWI) response.