• The Korean Journal of Mycology
• /
• v.38 no.2
• /
• pp.152-159
• /
• 2010

The influence of urushiol, as an allergen on laccase property of Fomitella fraxinea was investigated. The enzyme production was reached to the highest level after 10 days, cultivation and the activity and mycelial biomass were increased by 2.5 and 1.5 folds, respectively, by adding urushiol in the culture medium. In liquid cultures using a Cu Mn-free medium, laccase lactivity was decreased by 3.8-9.2 folds, with similar dry cell weight. Two isoenzymes, were purified using anion exchange, hydrophobic interaction and size-exclusion chromatographies. Both isoenzymes are monomeric proteins, with $M_W$ around 67 kDa(Lac1) and 66 kDa(Lac2), and isoelectric points of 3.67 and 3.81. The optimal conditions for purified isoenzymes were found to be pH 4.5-5.0 and $30-35^{\circ}C$. Activity decreased by the addition of $Fe^{2+}$, $Mg^{2+}$, $Na^+$, and strongly inhibited by EDTA and sodium azide.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.4
• /
• pp.547-557
• /
• 1996

Background : An excessive accumulation of neutrophils in lung tissue has been known to play an important role in mediating the tissue injury among the adult respiratory distress syndrome, idiopathic pulmonary fibrosis and cystic fibrosis by releasing toxic oxygen radicals and proteolytic enzymes. Therefore, it is important to understand a possible mechanism of neutrophil accumulation in lung tissue. In many species, exposure to hyperoxic stimuli can cause changes of lung tissues very similar to human adult respiratory distress syndrome and neutrophils are also functioning as the main effector cells in hyperoxic lung injury. The purpose of the present study was to examine whether neutrophils function as a key effector cell and to study the nature of possible neutrophil chemotactic factors found in bronchoalveolar lavage fluid from the hyperoxia exposed rats. Methods : We exposed the rats to the more than 95% oxygen for 24, 48, 60 arid 72 hours and bronchoalveolar lavage(BAL) was performed. Neutrophil chemotactic activity was measured from the BAT- fluid of each experimental groups. We also evaluated the molecular weight of neutrophil chemotactic tractors using fast performance liquid chromatography and characterized the substances by dialyzer membrane and heat treatment. Results : 1) The neutrophil proportions in bronchoalveolar lavage fluid began to rise from 48 hours after oxygen exposure, and continued to be significantly increased with exposure times. 2) chemotactic index for neutrophils in lung lavages from rats exposed to hyperoxia was significantly higher in 48 hours group than in control group, and was significantly increased with exposure time. 3) No deaths occured until after 48 hours of exposure. However, mortality rates were increased to 33.3 % in 60 hours group and 81.3 % in 72 fours group. 4) Gel filtration using fast performance liquid chromatography disclosed two peaks of neutrophil chemotactic activity in molecular weight of 104,000 and 12,000 daltons. 5) Chemotactic indices of bronchoalveolar lavage fluid were significantly deceased when bronchoalveolar lavage fluid was treated with heat ($56^{\circ}C$ for 30 min or $100^{\circ}C$ for 10 min) or dialyzed (dialyzer membrane molecular weight cut off : 12,000 daltons). Conclusion : These results suggested that the generation of neutrophil chemotactic factor and subsequent neutrophil influx into the lungs are playing an important roles in hyperoxia-induced acute lung injury. Neutrophil chemotactic factor in the lung lavage fluids consisted of several distinct components having different molecular weight and different physical characteristics.

• The Journal of the Korean Society for Microbiology
• /
• v.21 no.1
• /
• pp.151-161
• /
• 1986

In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

• Parasites, Hosts and Diseases
• /
• v.24 no.2
• /
• pp.177-186
• /
• 1986

This study was designed to evaluate the partially purified antigens which were fractionated from crude extract of Paragonimus westermani and to monitor the enzyme-linked immunosorbent assay (ELISA) in experimental cat paragonimiasis during the course of infection as well as before and after chemotherapy. Crude extract of 6-month-old adult P. westermani was fractionated to 5 antigens by successive applications of ammonium sulfate precipitation, ion exchange chromatography and gel filtration. And the cats, 10 in each group, were infected with 60, 30, 15, and 5 metacercariae, then the half of each group was treated with praziquantel 2 times in one day of 100mg per kilogram of weight on 150 days after the infection. Sera were collected every 10 days. ELISA was performed with the concentration of $2{\mu}g/ml$ antigen, 100 times diluted sera and 1,000 times diluted alkaline phosphatase conjugated anti-cat IgG. The results were as follows: 1. Absorbance by ELISA with proteins precipitated by differential concentration of ammonium sulfate was the highest at $51{\sim}65%$ precipitate (PA2), followed by $0{\sim}50%$ precipitate (PAl), $66{\sim}80%$ precipitate (PA3), and $81{\sim}90%$ precipitate (PA4). Unprecipitated protein over 90% ammonium sulfate (PA5) showed the lowest antigenicity. 2. Fractionation of PA1, PA2, and PA3 through the DEAE-cellulose column did not differentiate the antigenic proteins. 3. By passing through the Sephadex G-200 column, PA1 and PA2 were fractionated to high molecular weight proteins and those of low molecular weight which showed high absorbance by ELISA (PA1-I, II and PA2-I, II). But PA3 was shown to have a fraction of high molecular weight proteins (PA3-I) which showed high antigenicity. 4. SDS-polyacrylamide gel electrophoresis of PA1-I, P A1-II, PA2-I, PA2-II, PA3-I, and crude extract was performed. Fraction PA1-I was composed of proteins which had the molecular weight of 270 kilodaltons(KD) to 196 KD; of them 220KD protein was major band. Fraction PA2-I was composed of $255{\sim}225\;KD$, and PA3-I, $255{\sim}240\;KD$, respectively. Fraction PA1-II and fraction PA2-II consisted of 30 KD proteins. 5. Absorbance by ELISA began to increase within $10{\sim}20$ days after the infection and reached the highest on $140{\sim}180$ days, then made plateau thereafter. 6. Absorbance by ELISA decreased after praziquantel treatment. In 60 metacercariae infection group, the absorbance had been decreasing, but remained within the positive range during observation period, while those of 30, 15, and 5 metacercariae infection groups turned to negative range. 7. Fraction PA1-II showed the highest antigenicity in ELISA, then fraction PA2-I, fraction PA1-I, fraction PA2-II, fraction PA3-I and crude extract followed. In early phase of infection, the absorbance of fraction PA1-II showed more rapid increase than those of the other fractions and it came to positive range at $20{\sim}30$ days after infection.

• Journal of Nutrition and Health
• /
• v.36 no.1
• /
• pp.9-17
• /
• 2003

The preparation method of a soluble dietary fiber from oak wood (Quercus mongolica) and the effect of the soluble dietary fiber on physiological function in rat fed high cholesterol diets was investigated. The best condition for steam explosion method was 25 kgf/㎤ pressure for 6 min. The exploded samples were delignified by the filtration treatment with 1% NaOH for several times, which is the best condition. The enzymatic hydrolysis of Cellusoft cellulase was more effective than Onozuka R-10 cellulase. The manufactured soluble dietary fiber was assayed using gel permeation chromatography (GPC) and it was dissolved in water. Average molecular weight distribution of manufactured soluble dietary fiber was about 348-1,200 and it was assumed the oligomer form fraction. In order to compare the manufactured soluble dietary fiber with commercial soluble dietary fiber (pectin) on the physiological function, Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to one normal diet and five high cholesterol diet containing 1% cholesterol. The high cholesterol diet groups were classified to fiber free diet (FF group), 5% pectin (5P group), 10% pectin (l0P group), 5% manufactured soluble dietary fiber (5M group) and 10% manufactured soluble dietary fiber (10M group). Body weight gains in all soluble dietary fiber groups were lower than FF group. Food intakes were increased in all soluble dietary fiber groups than that of FF group. Food efficiency ratio (FER) was significantly decreased in all soluble dietary fiber groups than that of the FF group, and it was especially was highest in 10% supplemented soluble dietary fiber group. The weight of liver of the soluble dietary fiber supplemented groups were lower than those of the FF group, but weights of cecum and small intestine of all supplemented soluble dietary fiber groups were significantly increased, compared with that of FF group. The weights and water contents in feces were significantly increased by the soluble dietary fiber. The activity of the glutamic oxaloacetic transaminase in soluble dietary fiber groups were significantly decreased than those of FF group. The hepatic glutathione S-transferase activity in all soluble dietary fiber supplemented groups were higher than that of FF group. The physiological effects of the manufactured soluble dietary fiber are the same as the commercial soluble dietary fiber (pectin). The preparation method of the soluble dietary fiber from the oak chips suited to its purpose. (Korean J Nutrition 36(1) : 9~17, 2003)

• Journal of Life Science
• /
• v.19 no.9
• /
• pp.1218-1225
• /
• 2009

Difractose anhydrides (DFAs) is studied as a sweetener for diabetics because of its structural property. DFAs have four types: DFA I, III, IV (degradation of levan) and V (degradation of inulin). Especially, DFA IV has been shown to enhance the absorption of calcium in experiments using rats. Levan fructotransferase is an enzyme for producing di-d-fructose-2,6':6,2-dianhydride (DFA IV). To identify structural characterization, we purified wild-type and mutants (D63A, D195N and N85S) of levan fructotransferase (LFTase) from Microbacterium sp. AL-210. These proteins were purified to apparent homogeneity by Ni-NTA affinity column, Q-sepharose ion exchange and gel filtration chromatography and detected by SDS-PAGE. They were also analyzed by circular dichroism (CD) measurements, JNET secondary structure prediction, activity measurements at various temperatures, and pH analysis. The optimum pH for the enzyme-catalyzed reaction was pH 7.5 and optimum temperature was observed at $55^{\circ}C$. Along with wild-type LFTase, mutants were analyzed by CD measurement, fluorescence analysis and differential scanning calorimetry (DSC). N85S showed less $\alpha$-helix and more $\beta$ strand than others. Also, N85S showed almost the same curve as wild-type in their steady-state fluorescence spectra, whereas mutant D63A and D195N showed higher intensity than wild-type. The amino acid sequence of wild-type LFTase was compared to the sequences of exo-inulinase from Aspergillus awamori, a plant fructan 1-exohydrolase from Cichorium intybus, and Thermotogo maritime (Tm) invertase and showed a high identity with Exo-inulinase from Aspergillus awamori.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.202-210
• /
• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.