• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.318-323
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• 1995

The effect of AF-toxin I produced by the strawberry pathotype of Alternaria alternata on the protein synthesis of susceptible strawberry protoplasts was examined by using the radiolabeled amino acids. The incorporation of the radiolabeled amino acids into newly synthesized proteins in the strawberry protoplasts was stimulated by the toxin treatment at relatively low concentrations (2.2$\times$10-11 to 2.2$\times$10-9 M), but not at higher concentrations (2.2$\times$10-8 to 2.2$\times$10-6 M). An one-dimensional SDS-polyacrylamide gel electrophoresis revealed no detectable differences in the proteins synthesized in both the toxintreated and untreated protoplasts. The susceptible strawberry protoplasts were treated with AF-toxin I and stained with Fluostain I to detect the extracellular polysaccharides. The toxin treatment induced the accumulation of extracellular polysccharides in a dose-dependent manner. These results indicate a transient activation of cellular metabolism in the susceptible cells by the toxin exposure.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.872-877
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• 2013

In a previous study, we isolated and reported a second species of the Saccharophagus genus, Saccharophagus sp. strain Myt-1. In the present study, an alginate lyase gene (algMytC) from the genomic DNA of Myt-1 was cloned and characterized. The DNA sequence fragment obtained contained an open reading frame of 1,032 bp that encoded a protein of 343 amino acids with an estimated molecular mass of 37.6 kDa and a pI of 6.60. The deduced protein, AlgMytC, had the conserved amino acid sequences (RTELREM, QIH, YFKAGVYNQ) of the polysaccharide lyase family 7. A BLAST homology search indicated that AlgMytC shared an amino acid sequence identity of 95.9% with alg7A of S. degradans 2-40. The cloned and purified AlgMytC protein showed optimal activity at $40^{\circ}C$, and retained more than 90% of its total activity even after treatment at $25^{\circ}C$ for 24 h. AlgMytC was very alkaliphilic with an optimal pH of 9.0, and more than 90% of its activity was retained in the pH range 8.5-10.0. Moreover, AlgMytC was stable over a wide pH range. The activity of AlgMytC was also stable in the presence of various detergents.

• BMB Reports
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• v.42 no.3
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• pp.172-177
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• 2009

Phosphoglucose isomerase (PGI) is involved in synthesizing extracellular polysaccharide (EPS). The gene encoding PGI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli, and the protein was characterized. The pgi gene from DJ77 is 1,503 nucleotides long with 62% GC content and the deduced amino acid sequence shows strong homology with PGIs from other sources. The molecular masses of PGI subunit and native form were estimated to be 50 kDa and 97 kDa, respectively. Four potentially important residues (H361, R245, E330 and K472) were identified by homology modeling. The mutations, H361A, R245A, E330A, R245K and E330D resulted in decrease in Vmax by hundreds fold, however no significant change in Km was observed. These data suggest that the three residues (H361, R245Aand E330) are likely located in the active site and the size as well as the spatial position of side chains of R245 and E330 are crucial for catalysis.

• BMB Reports
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• v.42 no.8
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• pp.523-528
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• 2009

Phosphomannose isomerase (PMI) catalyzes the interconversion of fructose-6-phosphate and mannose-6-phosphate in the extracellular polysaccharide (EPS) synthesis pathway. The gene encoding PMI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli. The pmi gene is 1,410 nucleotides long and the deduced amino acid sequence shares high homology with other bifunctional proteins that possess both PMI and GDP-mannose pyrophosphorylase (GMP) activities. The sequence analysis of PMI revealed two domains with three conserved motifs: a GMP domain at the N-terminus and a PMI domain at the C-terminus. Enzyme assays using the PMI protein confirmed its bifunctional activity. Both activities required divalent metal ions such as $Co^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $Ni^{2+}$ or $Zn^{2+}$. Of these ions, $Co^{2+}$ was found to be the most effective activator of PMI. GDP-D-mannose was found to inhibit the PMI activity, suggesting feedback regulation of this pathway.

• The Korean Journal of Mycology
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• v.10 no.4
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• pp.147-154
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• 1982

To find antitumor components with low toxicity from natural resources, antitumor test of the water extract of the carpophores of Trametes sanguinea (L. ex Fr.) Lloyd. was undertaken. The carpophores of this fungus were collected in Gyeong Gi Province and extracted with hot water. The extract was purified by dialyzing through Visking tube and a protein-bound polysaccharide fraction was obtained. The fraction was tested for antitumor activity against sarcoma 180 implanted in mice. The tumor inhibition ratio of the fraction against the tumor was 72.4% at the dose of 10mg/kg/day for the period of ten days. The tumor in one of the eight mice was completely regressed. The antitumor components were found to be a polysaccharide and a protein. The hydrolysis of the polysaccharide moiety yielded three monosaccharides, and from the hydrolysate of the protein moiety 13 amino acids were identified.

• The Korean Journal of Mycology
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• v.10 no.4
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• pp.165-171
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• 1982

To investigate antitumor components of Korean higher fungi, the carpophores of Ramaria formosa $(Fr.)Qu\acute{e}l$. were collected in Gang Won Province and extracted with hot water. The extract was concentrated and precipitated by four volumes of ethanol. The precipitate was centrifugated and purified by dialyzing through Visking tube and a protein-bound polysaccharide fraction was obtained. The fraction was tested for antitumor activity against sarcoma 180 implanted in mice. The tumor inhibition ratio of the fraction was 66% in the dose of 50mg/kg/day for the period of ten days. The tumor in two of the eight mice was completely regressed. The components of the fraction were found to be a polysaccharide and a protein. The chemical analysis of the fraction showed that the polysaccharide moiety consisted of four monosaccharides and that the protein moiety contained fourteen amino acids.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.670-677
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• 2010

An alkaline pectate lyase, Bsp165PelA, was purified to homogeneity from the culture broth of alkaliphilic Bacillus sp. N16-5. The enzyme showed a specific activity as high as 1,000 U/mg and had optimum activity at pH 11.5 and $50^{\circ}C$. It was composed of a single polypeptide chain with a molecular mass of 42 kDa deduced from SDS-PAGE, and its isoelectric point was around pH 6.0. It could efficiently depolymerize polygalacturonate and pectin. Characterization of product formation revealed unsaturated digalacturonate and trigalacturonate as the main products. The pectate lyase gene (pelA) contained an open reading frame (ORF) of 1,089 bp, encoding a 36-amino acids signal peptide and a mature protein of 326 amino acids with a calculated molecular mass of 35.943 Da. The deduced amino acid sequence from the pelA ORF exhibited significant homology to those of known pectate lyases in polysaccharide lyase family 1. Some conserved active-site amino acids were found in the deduced amino acid sequence of Bsp165PelA. $Ca^{2+}$ was not required for activity on pectic substrates.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.68-74
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• 2015

Based on the genomic analysis of Thermococcus pacificus P-4, we identified a putative GH1 ${\beta}$-glucosidase-encoding gene (Tpa-glu). The gene revealed a 1,464 bp encoding 487 amino acid residues, and the deduced amino acid residues exhibited 77% identity with Pyrococcus furiosus ${\beta}$-glucosidase (accession no. NP_577802). The gene was cloned and expressed in Escherichia coli system. The recombinant protein was purified by metal affinity chromatography and characterized. Tpa-Glu showed optimum activity at pH 7.5 and $75^{\circ}C$, and thermostability with a half life of 6 h at $90^{\circ}C$. Tpa-Glu exhibited hydrolyzing activity against various pNP-glycopyranosides, with kcat/Km values in the order of pNP-${\beta}$-glucopyranoside, pNP-${\beta}$-galactopyranoside, pNP-${\beta}$-mannopyranoside, and pNP-${\beta}$-xylopyranoside. In addition, the enzyme exhibited exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharide (laminarin) and ${\beta}$-1,3- and ${\beta}$-1,4-linked oligosaccharides. This is the first description of an enzyme from hyperthermophilic archaea that displays exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharides and could be applied in combination with ${\beta}$-1,3-endoglucanase for saccharification of laminarin.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.657-666
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• 1999

The first option in manure management is developing an environmentally sound nutritional management. This includes proper feeding programs and feeds which will result in less excreted nutrients that need to be managed. Critical components that should be controlled are N, P and minerals that are used at supranutritional levels. Amino acid supplementation and protein restriction reduce N excretion in the monogastric animals. Supplementation with enzymes, such as carbohydrases, phytase and proteases, can be used to reduce excretion of nutrients and feces by improving digestibility of specific nutrients. Growth promoting agents, such as antibiotics, beta-agonists and somatotropin, increase the ability of animals to utilize nutrients, especially dietary protein, which results in reduced excretion of N. Some microminerals, such as Cu and Zn, are supplemented at supranutritional level. Metal-amino acid chelates, metal-proteinates and metal-polysaccharide complexes can be used at a much lower level than inorganic forms of metals without compromising performance of animals. Deodorases can be used to avoid air pollution from animal manure. Nutritional management increases costs to implement. It is necessary to assess the economics in order to find an acceptable compromise between the increased costs and the benefits to the environment and production as well.

• Mycobiology
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• v.36 no.1
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• pp.50-54
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• 2008

This study examined the chemical composition of A. blasiliensis and the chemical structural properties of an immuno-stimulating polysaccharide. The amino acids, free sugars, and organic acids by HPLC and fatty acids by GC were analyzed. The immuno-stimulating substance from A. blasiliensis was extracted with hot water and purified by ethanol precipitation. It underwent ion exchange chromatography on DEAE-cellulose and gel filtration on Toyopearl HW 65F. Through GP-HPLC, the substance was found to be homogeneous. Its chemical structure was determined by $^{13}C-NMR$. Fatty acids, organic acids, and sugar alcohol composition consisted exclusively of linoleic acid, fumaric acid and mannitol, respectively. The amino acids were mainly glutamic acid, glycine, and arginine. By $^{13}C-NMR$ analysis, the immuno-stimulating substance was identified as ${\beta}-(1{\rightarrow}3)\;(1{\rightarrow}6)$-glucan, composed of a backbone with $(1{\rightarrow}3)$-linked D-glucopyranosyl residues branching a $(1{\rightarrow}6)$-linked D-glucopyranosyl residue. The ${\beta}$-glucan from A. blasiliensis showed pronounced immuno-stimulating activity on the antibody-production ability of B-lymphocytes by the hemolytic suspension assay. In these results, A. blasiliensis was estimated to have potent pharmacological properties and potential nutritional values.