• Parasites, Hosts and Diseases
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• v.32 no.2
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• pp.101-110
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• 1994

This report describes the structures of high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by the microfilariae of Diroflcrio immitis. Microfilariae of D. immitis were incubated in vitro in media containing 2-(3H) mannose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with pronase and fractionation by chromatography on concanavalin A Sepharose. Thirty eight percent of 2- (3H) mannose incorporated into the microalariae of D. immitis glycopeptides was recovered in high mannose-type asparagine-linked oligosaccharides which were bound to the immobilized lectin. Upon treatment of 2-(3H) mannose labeled glycopeptides with endo - β- N- acetylglu co saminidase H , the high mannose type chains were released and their structures were determined by high performance liquid chromatography and exoglycosidase digestion. The major species of high mannose-type chains synthesized by microfilariae of D. immitis have the composition Man5GlcNAc2, Man6ClcNAc2, Man7GlcNAc2, and Man8GlcNAc2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by vertebrates.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.555-558
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• 2006

The chemical reduction of Pseudomonas syringae subsp. phaseolicola alginates produces neutral polymers of D-mannose and L-gulose in source specific ratios. L-Gulose was highly sensitive to degradation by 1N HCl at $100^{\circ}C$. As hydrolysis time increased, gulose recovery decreased to 22% after 4 hr, whereas 98% of the D-mannose was recovered under the same conditions. Thin layer chromatography showed the formation of a second product upon L-gulose acid hydrolysis. This new product had a rate of flow (Rf) value of 0.58, identical to that of 1,6 anhydro-${\beta}$-D-mannopyranose and very close to that of 1,6 anhydro-${\beta}$-D-glucopyranose (Rf=0.60). Because of the difference in acid sensitivity between L-gulose and D-mannose, normal acid hydrolytic techniques applied to reduced alginates produces erroneous mannuronic acid (M): guluronic acid (G) ratio's unless one accounts for the differential rates of destruction of each sugar.

• Journal of Life Science
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• v.18 no.6
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• pp.782-788
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• 2008

The aim of this work is to show differences in the pattern of glycoconjugate composition in the intestines of four teleostean species (Sebastes schlegeli, Halichoeres poecilopterus, Bryzoichthys lysimus, and Takifugu pardalis). We compared four regions of all species studied. The specimens were processed and stained with nine kinds of biotinylated lectins (DBA, SBA, PNA, BSL- I , RCA- I , sWGA, UEA- I , LCA and Con A). Except for Sebastes schlegeli, no differences between regions were observed. The intestinal epithelium of Halichoeres poecilopterus possessed D-glucose/mannose residues in all regions. ${\beta}$-N-acetyl-D-galactosamine was distinctive along the intestines, although the pattern of diversity was different in Sebastes schlegeli, Bryzoichthys lysimus, and Takifugu pardalis. Additionally, the occurrence of Galactose-${\beta}$-1,3-N-acetyl-D-galactosamine and ${\alpha}$-D-galactose were confirmed in the proximal, middle, and distal intestine of Sebastes schlegeli, while rectal intestine lacked these sugar residues. Along with ${\beta}$-N-acetyl-D-galactosamine, ${\beta}$-N-acetyl-D-glucosamine and D-glucose/mannose were also determined in Bryzoichthys lysimus. Galactose-${\beta}$-1,3-N-acetyl-D-galactosamine, D-galactose, and D-glucose/mannose were also present in Takifugu pardalis.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.591-597
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• 1993

Two new 6-azauracil dioxolane nucleosides which are related to Dioxolane T and expected to have anti-HIV activity were asymmetrically synthesized. The key intermediate 8 have been synthesized in ten steps from D-mannose and condensed with 6-azauracil to give 13 and 14 after desilylation, respectively.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.365-369
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• 2012

Acanthamoeba spp. are single-celled protozoan organisms that are widely distributed in the environment. In this study, to understand functional roles of a mannose-binding protein (MBP), Acanthamoeba castellanii was treated with methyl-alpha-D-mannopyranoside (mannose), and adhesion and cytotoxicity of the amoeba were analyzed. In addition, to understand the association of MBP for amoeba phagocytosis, phagocytosis assay was analyzed using non-pathogenic bacterium, Escherichia coli K12. Amoebae treated with mannose for 20 cycles exhibited larger vacuoles occupying the most area of the amoebic cytoplasm in comparison with the control group amoebae and glucose-treated amoebae. Mannose-selected amoebae exhibited lower levels of binding to Chinese hamster ovary (CHO) cells. Exogenous mannose inhibited >50% inhibition of amoebae (control group) binding to CHO cells. Moreover, exogenous mannose inhibited amoebae (i.e., man-treated) binding to CHO cells by <15%. Mannose-selected amoebae exhibited significantly decreased cytotoxicity to CHO cells compared with the control group amoebae, 25.1% vs 92.1%. In phagocytic assay, mannose-selected amoebae exhibited significant decreases in bacterial uptake in comparison with the control group, 0.019% vs 0.03% (P<0.05). Taken together, it is suggested that mannose-selected A. castellanii trophozoites should be severely damaged and do not well interact with a target cell via a lectin of MBP.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.36-40
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• 1995

Yam(Dioscorea) tubers were used as one of the dietary starches in Korea, China and Japan because of its characteristic properties. Yam tubers were powdered after freeze drying the sliced tubers to investigate carbohydrates. Chemical properties such as proximate components and carbohydrates were studied using three varieties of Korean yams, namely. D. batatas, D. aimadoimo and D. japonica. The proximate components of yam tubers showed that the major components of Korean yam tubers were carbohydrates and moisture. The main components of free sugars in yams were identified as fructose, glucose, sucrose and maltose. In addition to these four sugars, there were two unidentifiable peaks whose areas are too big to ignore. These results were obviously different from other reported data of free sugars in yams. The main components of total sugars were mannose and glucose.

• Biomedical Science Letters
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• v.16 no.4
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• pp.221-227
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• 2010

To elucidate the invasion mechanism of pathogenic Naegleria fowleri, especially a receptor-ligand recognition, we investigated the in vitro cytotoxicity of pathogenic N. fowleri and nonpathogenic N. gruberi to murine macrophages, RAW 264.7, by adding four kinds of saccharides, ${\alpha}$-fucose, ${\beta}$-galactose, ${\alpha}$-D-mannopyranoside (${\alpha}$-mannose) and xylose. There was not enough of a difference in the cytotoxicity of N. fowleri treated with 10 mM of each saccharide. In particular, the cytotoxicity of N. fowleri was highly inhibited by 100 mM ${\alpha}$-mannose, which was 62.3% inhibition calculated by the analysis of lactate dehydrogenase (LDH) release assay. Although murine macrophages were not significantly destroyed by nonpathogenic N. gruberi under hematoxylin staining, the cytotoxicity of N. gruberi was inhibited from 31.5% to 14.5% (P<0.01) by 100 mM ${\alpha}$-mannose treatment. The binding of N. fowleri to macrophages was inhibited from 33% to 50% by 100 mM ${\alpha}$-mannose. Furthermore, as results of the adhesion assays which were performed to determine whether binding of Naegleria is mediated by saccharides-binding protein, the binding ability of N. fowleri as well as N. gruberi was inhibited by 100 mM ${\alpha}$-mannose.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.84-89
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• 2005

Phosphomannomutase (PMM) is a key enzyme in prokaryotes and eukaryotes, which catalyzes the conversion of ${\alpha}$-D-mannose 6-phosphate to ${\alpha}$-D-mannose 1-phosphate. The latter is the substrate for the synthesis of GDP-mannose, which serves as the mannosyl donor for many metabolic pathways in the cells. We report here on the isolation of a gene from a genomic library of Sphingomonas chungbukensis DJ77, the pmmC gene encoding phosphomannomutase. The gene was cloned into E. coli expression vector, and the sequence was analyzed. The ribosomal binding site GGAAG lays 5 bp upstream of the ORF of 750 bp, which is initiated by ATG codon and terminated by TAG. The predicted sequence of the enzyme consists of 249 amino acids with a molecular mass of 27.4 kDa and showed $86.9\%$ similarity to that of eukaryotic phosphomannomutase after bioinformatical analyses with the conserved domain search of NCBI. The purified gene product revealed the activity of phosphomannomutase. In conclusion, we confirmed that pmmC gene encodes phosphomannomutase actually.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.169-173
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• 2004

Parenchyma cells of Streptanthus tortus suspension cultures possessed the different transport system for aldose-formed D-glucose and for ketose-formed D-fructose. $K_{m}$ value for D-glucose and D-fructose were 0.28mM and 15.02mM, respectively. $K_{m}$ value of D-mannose was 0.44 mM which is similar to the D-glucose transport system, but D-mannose was transported also through its own special uptake system. Parenchyma cells possessed the transport system of L-glucose, but the function of L-glucose was not known at all. Protoplast of parenchyma cells possessed only the monosugars transport system, but didn't possess the disugars, sucrose transport system. Early developing phloem protoplasts possessed glucose and sucrose transport system at the same time. On the contrary, in the complete developed phloem cells disappeared preexisted glucose transport system in the parenchyma cells, only new induced sucrose transport system existed.ted.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1293-1298
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• 2018

Phosphomannomutase (ManB) converts mannose-6-phosphate (M-6-P) to mannose-1-phosphate (M-1-P), which is a key metabolic precursor for the production of GDP-D-mannose used for production of glycoconjugates and post-translational modification of proteins. The aim of this study was to express the manB gene from Escherichia coli in Lactococcus lactis subsp. cremoris NZ9000 and to characterize the encoded enzyme. The manB gene from E. coli K12, of 1,371 bp and encoding 457 amino acids (52 kDa), was cloned and overexpressed in L. lactis NZ9000 using the nisin-controlled expression system. The enzyme was purified by Ni-NTA column chromatography and exhibited a specific activity of 5.34 units/mg, significantly higher than that of other previously reported ManB enzymes. The pH and temperature optima were 8.0 and $50^{\circ}C$, respectively. Interestingly, the ManB used in this study had two substrate specificity for both mannose-1-phosphate and glucose-1-phosphate, and the specific activity for glucose-1-phosphate was 3.76 units/mg showing 70% relative activity to that of mannose-1-phosphate. This is the first study on heterologous expression and characterization of ManB in lactic acid bacteria. The ManB expression system constructed in this study canbe used to synthesize rare sugars or glycoconjugates.