• 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.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.528-533
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• 1995

An antiviral protein (AAP29) with ribosome-inactivating activity was purified and characterized from the leaves of the Amaranthus mangostanus. Purification was accomplished through crude extraction, ammonium sulfate precipitation, S-Sepharose chromatography, gel filtration, CM-Sepharose chromatography and Blue sepharose chromatography. This protein was about 29.2 kDa and strongly basic with the PI value between 9.0 and 9.6, indicating that AAP29 is similar to Type 1 RIP. The AAP29 showed high thermostability without activity toss even after 20 min at $50^{\circ}C$. In cell free system using rabbit reticulocyte lysate, AAP29 inhibited protein synthesis with an $IC_{50}$, of 0.18 nM. This protein also reduced mosaic symptoms of cucumber mosaic virus (CMV) on tobacco leaves. The N-terminal amino acid sequences of the AAP29 are ADLTFTVTKDGTSQSYXTLXNXWRXW and shows no sequence similarity with any known RIPs.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.638-643
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• 2007

The full encoding sequence for human type II hexokinase (HXK II) was cloned into the E. coli expression vector pET 21b and expressed as a C-terminally hexahistidine-tagged protein in the BL2l (DE3) strain. The IPTG-induced HXK II approximately accounted for 17% of the total E. coli proteins, and 81% of HXK $II_{6{\times}His}$ existed in inclusion bodies. To improve the production of soluble recombinant HXK II protein, in the functionally active form, we used low temperature, and the osmotic stress expression method. When expressed at $18^{\circ}C$, about 83% of HXK $II_{6{\times}His}$ existed in the soluble fraction, which amounted to a 4.1-fold yield over that expressed at $37^{\circ}C$. The soluble form of HXK $II_{6{\times}His}$ was also highly produced in the presence of 1M sorbitol under the standard condition $(37^{\circ}C)$, which indicated that temperature downshift and low water potentials were required to improve the yield of active recombinant HXK II protein. The expressed protein was purified by metal chelate affinity chromatography performed in an IDA Excellose column charged with $Ni^{2+}$ ions, resulting in about 40mg recombinant HXK II protein obtained with purity over 89% from 51 of E. coli culture. The identity of HXK $II_{6{\times}His}$ was confirmed by Western blotting analysis. Taken together, using the stress-governed expression described in this study, human active HXK II can be purified in sufficient amounts for biochemical and biomedical studies.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.310-315
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• 2011

BACKGROUND: Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their accumulation throughout the food chain leads to serious ecological and health problems. METHODS AND RESULTS: Optimum conditions in continuous-flow stirred tank reactor (CSTR) and packedbed column contactor (PBCC) using brown seaweed biosorbent were investigated. Under optimum conditions from both lab-scale biosorbent systems, removal efficiency of copper (Cu) in a large-scale PBCC system was investigated. Removal capacity of Cu using brown seaweed biosorbent in a lab-scale CSTR system was higher than that in a lab-scale PBCC system. On the other hand, over 48 L/day of flow rate in Cu solution, removal efficiency of Cu in a lab-scale PBCC system was higher than that in a lab-scale CSTR system. Optimum flow rate of Cu was 24 L/day, optimum Cu solution concentration was 100 mg/L. Removal capacity of Cu at different stages was higher in the order of double column biosorption system > single column biosorption system. Under different heavy metals, removal capacities of heavy metal were higher in the order of Pb > Cr > Ni > Mn ${\geq}$ Cu ${\geq}$ Cd ${\fallingdotseq}$ Zn ${\geq}$ Co. Removal capacity of Cu was 138 L in a large-scale PBCC system. Removal capacity of Cu a large-scale PBCC system was similar with in a lab-scale PBCC system. CONCLUSION(s): Therefore, PBCC system using brown seaweed biosorbent was suitable for treating heavy metal wastewater.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.311-316
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• 1987

From the results of triglyceride composition and the fatty acid at ${\beta}-position$ of glycerol, triglyceride molecular species of sunflower seed oil were found to be 26 kinds. The major triglyceride molecular species in sunflower seed oil were identified to PLL; 10.4%, OLL; 22.3%, and characterized that LLL species existed more than 31% of the total triglyceride molecular specie.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.3
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• pp.69-78
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• 2003

The main purpose of this study was to verify the shore margin protection effect of the root system of Salix gracilistyla Miq. developed from direct sticking cuttings on wetland, focusing on the effect of the root system reducing soil particle dissociation rate in water. The soil dissociation rate was examined through slaking tests with cylindric pure soil column at maximum particle density and the same size column of root reinforced soil. The dry weight of remained soil was measured after 5, 10, 15, 30minutes and 1, 6, 12, 24, 48hours inundation. As results, the soil particles began to dissociate severely at 10 minutes and only 10% of soil particles were left after 25minutes inundation. The stable slope angle of pure soil was $36^{\circ}$after 24 hours. On the other hand, the columns of root reinforced soil were stable even after 24hours, being dissociated only 7.2% of soil particles. So, it was revealed that the root system was very effective materials protecting more than 80% of soil particle from dissociation in inundation.

• Korean Journal of Microbiology
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• v.26 no.2
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• pp.73-81
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• 1988

$\alpha$-Amylase (EC.3.2.1.1) of Neurospora crassa (ATCC9279) was cloned in E. coli HB101 using shotgun method, and the enzymes isolated from both N. crassa and E. coli were compared. Chromosomal DNA isolated from the spores of N. crassa was partially digested with PstI restriction endonuclease and rejoined to pBR322 which had been digested with the same enzyme. The resulting recombinant DNA were introduced into E. coli HB101 which had competancy by treating with $CaCl_{2}$. As the result, about 8000 colonies which showed tetracycline resistance were selected and two of the colonies which had 13.5Kb recombinant plasmid exhibit starch degrading activity on starch-containing plate when treated with D-cycloserine. $\alpha$-Amylases from both N.crassa and E. coli were isolated by using ammonium sulfate precipitation, DEAE-cellulose ion exchange column chromatography and Bio-Gel P150 gel foltration column. As the result, about 81.3 fold and 5.6 fold purifications in specific activities were obtained respectively, and specific activities of the gel filtrates were 6.1u/mg and 85u/mg respectively. The properties of both enzymes were compared and they showed quite the similar patterns in optimal temperature, optimal pH and had same molecular weight about 100,000 daltons on gel filtration method. Optimal temperatures for both enzymes were $70^{\circ}C$ and optimal pH were about 6 and 10.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.19-23
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• 2016

A phenol substance was extracted from Pinus koraiensis Siebold et Zucc leaf extracts and its biological efficacy was measured. The highest content of the phenol substance contained in Pinus koraiensis Siebold et Zucc leaves was 13.5 mg/g, which was obtained when it was extracted with 80% ethanol. At a concentration of 200 mg/mL, the phenolic substances extracted with 80% ethanol and water showed antimicrobial activities against Helicobacter pylori, producing clear zones of 10 and 12 mm diameter, respectively. Pinus koraiensis Siebold et Zucc. leaf extracts were separated using a Sephadex LH-20 column and 4 fractions were obtained (fractions A-D). Fractions C and D showed the greatest inhibitory activity against Helicobacter pylori producing 10.1 and 12.3 mm clear zones, respectively. These two fractions were purified using a Sephadex LH-20 and MCI-gel column ($H_2O{\rightarrow}100%$ ethanol). Purified compounds A and B were identified as syringic acid and compound C was identified as p-coumaric acid based on $^1H$-nuclear magnetic resonance (NMR), $^{13}C$-NMR, and fast atom bombardment mass spectrometry spectra. When two or more purified compounds were mixed, a synergistic effect of anti-Helicobacter pylori activity was evident. This result indicates that extracts of Pinus koraiensis Siebold et Zucc leaves could be considered a functional food because of their high antimicrobial properties.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.551-558
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• 2016

Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) bark was collected, air-dried and extracted with 70% aqueous acetone, then concentrated and sequentially fractionated using n-hexane, methylene chloride ($CH_2Cl_2$), ethylacetate (EtOAc), and $H_2O$. The $H_2O$ fraction was chromatographed on a Sephadex LH-20 column with various aqueous MeOH eluting solvents to isolate an ellagitannin. The isolate was elucidated as macabarterin, a polyoxygenated ellagitannin by NMR analysis, including HSQC, HMBC, Q-TOF MS, and with the comparison of authentic literature data. The compound was an ellagitannin which was isolated, for the first time, from the extracts of Katsura tree bark, and has never been reported before in domestic tree or plant sources.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.114-118
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• 2002

Phenalamides $A_1{\sim}A_3$ were reisolated as cytotoxic substances from culture broth of Myxococcus stipitatus JW111. The producing strain was isolated from the marine sediment collected off the shore of Geomun Island, Korea. The active principles were extracted from cell mass with acetone and successively purified by silica gel column chromatography, Sephadex LH-20 column chromatography, and finally recycling prep. HPLC. These compounds demonstrated significant cytotoxicity against certain human cancer cells, having $IC_50$ values ranging from 0.23 to 0.50 ${\mu}g/ml$. Moreover, they also inhibited the growth of adriamycin-resistant HCT/ADM human cancer cell line as well as its parent sensitive cell line.