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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Life Science
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Journal DOI :
Korean Society of Life Science
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Volume & Issues
Volume 14, Issue 6 - Dec 2004
Volume 14, Issue 5 - Oct 2004
Volume 14, Issue 4 - Aug 2004
Volume 14, Issue 3 - Jun 2004
Volume 14, Issue 2 - Apr 2004
Volume 14, Issue 1 - Feb 2004
Selecting the target year
A Study on the Composition of Cordyceps militaris Extract and Mycelium
Journal of Life Science, volume 14, issue 5, 2004, Pages 727~731
DOI : 10.5352/JLS.2004.14.5.727
The composition of fruit body extract and mycelium in Cordyceps militaris has been investigated to determine the nutritional value. The nutritional compositions of fruit body extract were as follows; the content of crude fat, carbohydrate, crude protein were 0.16%, 3.10% and 1.05%, respectively. And content of crude fat, carbohydrate, crude protein in mycelium were 14.01 %, 54.70% and 20.54%, respectively. Potassium concentration in 1.36 g/100ml sample of fruit body extract was high up to 79.09 mg/100 g and Ca, P, Mg, Na, Mn, Zn and Cu were followed. As well, potassium concentration in 0.50 g/100 ml sample of mycelium was high up to 1,679.96 mg/100 g and P, Mg, Ca, Na, Fe, Mn, Zn and Cu were followed. There were 21 and 22 amino acids in fruit body extract and mycelium, respectively. The total content of 21 amino acids in fruit body extract was 223.78 mg/100 ml. It is more than 147.40 mg/100 ml which total content of 22 amino acid in mycelium. But the total content of essential amino acids in mycelium were higher than fruit body extract. The total content of 10 vitamin in fruit body and mycelium were 13.88 mg/100 g and 221.23 mg/100 g respectively, and the total content of vitamin in mycelium was sixteen times as more as fruit body extract.
Effect of E-box and E2F Binding Site on Transcriptional Activity in MCM Promoter
Journal of Life Science, volume 14, issue 5, 2004, Pages 732~740
DOI : 10.5352/JLS.2004.14.5.732
MCM proteins are essential for eukaryotic DNA replication, playing roles in the initiation and elongation of DNA replication. MCM proteins expression is much higher in malignant tissues than normal tissues. Several reports have indicated the usefulness of MCM proteins as markers of cancer cells in histopathological diagnosis. However, the cause of enhanced expression of MCM proteins in cancer cells remain to be clarified. The purpose of this study is to examine the relative transcriptional activities of human mcm gene promoters in cancer and normal cells. The minimal promoter region required for transcription of a luciferase reporter gene was contained an E-box and one E2F site. In addition, luciferase activities from mcm7 and mcm2 promoter/luciferase gene reporter constructs were significantly increased in cancer cells at 8 times compared with normal cells. E-box and E2F binding site in the promoter of mcm genes are responsible for different mechanism of transcription regulation on the cellular environment.
Effects of Different Exercise Intensities on GLUT-4 and GRP-78 Protein Expression in Soleus Muscle of Streptozotocin-Induced Diabetic Rats with Caffeine Oral Administration
Yoon, Jae-Suk ; Yoon, Jin-Hwan ;
Journal of Life Science, volume 14, issue 5, 2004, Pages 741~746
DOI : 10.5352/JLS.2004.14.5.741
This study investigated the response of GLUT-4 and GRP-78 protein expression in soleus muscle of Streptozotocin-induced diabetic rats with caffeine oral administration by imposing different exercise intensities. Rats were randomly divided into 5 groups (n
Hypocholesterolemic Effect of Yogurt Supplemented Salicornia herbacea Extract in Cholesterol-Fed Rats.
Journal of Life Science, volume 14, issue 5, 2004, Pages 747~751
DOI : 10.5352/JLS.2004.14.5.747
The effect of yogurt containing Hamcho (Salicornia herbacea) extract (Hamcho yogurt: HY) on the lipid concentrations in male Sprague-Dawley rats fed a cholesterol diet were studied. Rats were assigned three groups in the experiment; cholesterol diet (the CHOL group), cholesterol diet plus yogurt by lactic acid bacteria (the Y group) or cholesterol diet plus yogurt supplemented Hamcho extract by lactic acid bacteria (the HY group). Fermented milk with or without Hamcho extract in the diet supplemented at the levels 5.0% for 3 weeks. The concentrations of total cholesterol and bile acid in serum was significantly lower in the HY group than the CHOL group. This effect was also observed in rats fed a diet supplemented fermented milk. This cholesterol-lowering effect was more pronounced in the HY group compared to the Y group. The atherogenic index was significantly lower in the HY or Y groups than the CHOL group. The concentration of non esterified fatty acid in serum was significantly lower in the HY group than the CHOL and the Y groups. These results suggested that Hamcho yogurt exert the hypocholesterolemic effect in cholesterol fed rats.
Structural and Functional Analysis of Nitrogenase Fe Protein with MgADP bound and Amino Acid Substitutions
Jeong, Mi-Suk ; Jang, Se-Bok ;
Journal of Life Science, volume 14, issue 5, 2004, Pages 752~760
DOI : 10.5352/JLS.2004.14.5.752
The function of the [4Fe-4S] cluster containing iron (Fe-) protein in nitrogenase catalysis is to serve as the nucleotide-dependent electron donor to the MoFe protein which contains the sites for substrate binding and reduction. The ability of the Fe protein to function in this manner is dependent on its ability to adopt the appropriate conformation for productive interaction with the MoFe protein and on its ability to change redox potentials to provide the driving force required for electron transfer. The MgADP-bound (or off) conformational state of the nitrogenase Fe protein structure described reveals mechanisms for long-range communication from the nucleotide-binding sites to control affinity of association with the MoFe protein component. Two pathways, termed switches I and II, appear to be integral to this nucleotide signal transduction mechanism. In addition, the structure of the MgADP bound Fe protein provides the basis for the changes in the biophysical properties of the [4Fe-4S] observed when Fe protein binds nucleotides. The structures of the nitrogenase Fe protein with defined amino acid substitutions in the nucleotide dependent signal transduction pathways of the Switch I and Switch II have been determined by X-ray diffraction methods. These two pathways have been also implicated by site directed mutagenesis studies, structural analysis and analogies to other proteins that utilize similar nucleotide dependent signal transduction pathways. We have examined the validity of the assignment of these pathways in linking the signals generated by MgATP binding and hydrolysis to macromolecular complex formation and intermolecular electron transfer. The results provide a structural basis for the observed biophysical and biochemical properties of the Fe protein variants and interactions within the nitrogenase Fe protein-MoFe protein complex.
Biological Control of Perilla Sclerotinia Rot Caused by Sclerotinia sclerotiorum Using Bacillus megaterium N4.
Journal of Life Science, volume 14, issue 5, 2004, Pages 761~769
DOI : 10.5352/JLS.2004.14.5.761
This study was investigated the occurrence of sclerotinia rot caused by Sclerotinia sclerotiorum at the major perilla cultivating area, Gangdong-dong, Gangseo-gu, Busan in 1998. The incidence of this disease ranged from 8.1 to 28.3% at Gangdong-dong area during the growing seasons. Symptoms of the disease initially appeared damping-off of infected stems and soft-rot on the leaves of perilla. Under the relatively high humidity, abundant white mycelia of the pathogen formed on the lesion developed into black sclerotia later and the infected leaves were finally fell down. Sixteen isolates, Sl-S16, isolated from diseased lesions showing typical symptoms, and pathogenicity was tested using mycerlial disks. Among them, S2 isolate showing the most strong pathogenicity was selected and identified as Sclerotinia sclerotiorum on the basis of morphological and cultural characteristics. For biological control, an antagonistic bacteria, N4 isolate which effectively inhibited not only mycelial growth of S2 isolate but also suppress sclerotinia rot on the pot assay, was selected and identified as Bacillus megaterium according to Bergey`s manual and API system., Wettable powder type, N4 formulation using B. megaterium N4 isolate was developed and estimated its control effect on perilla crops in a plastic house. As a results, N4 formulation which applied before 3 days inoculation of pathogen was effectually controlled Sclerotinia rot as the control value of 98.0%, was more effective than chemical fungicide, benomyl showing the control value of 78.0%. This is the first report of wettable powder formulation as a biocontrol agent using B. megaterium N4 against Sclerotinia rot caused by S. sclerotiorum on perilla.
Functions of a-Tropomyosin Are Mainly Dependent upon the Local Structures of the Amino Terminus
Cho, Young-Joon ;
Journal of Life Science, volume 14, issue 5, 2004, Pages 770~777
DOI : 10.5352/JLS.2004.14.5.770
It has been previously reported that unacetylated a-tropomyosin(TM) produced in E. coli failed to bind to actin while acetylated muscle TM and Ala-Ser dipeptide fusion TM (AS-TM) bound well to actin. In order to determine the structural requirement of the amino terminus for high actin affinity, a recombinant tropomyosin (Ala-TM) that a single Ala residue was added to the amino terminus of Ala-TM was constructed, overexpressed, and purified from E. coli. Actin affinity of Ala-TM was 2.3
, whereas that of unacetylated TM was considerably lower than 0.1
indicating that addition of a single Ala residue to the amino terminus drastically increased, at least twenty times, actin affinity of TM. Ala-TM, however, bound to actin about three times weaker than acetylated TM and AS- TM, implying that the addition of an Ala residue was insufficient for complete restoration of high actin affinity. While Ala-TM, AS-TM, and muscle TM showed inhibition and activation of actomyosin Sl ATPase activity depending on myosin Sl concentration, the degree of inhibition and activation was different from each other. AS-TM exhibited the greatest inhibition of the ATPase at low Sl concentration, whereas the greatest activation of the ATPase was observed with muscle TM. These results, together with previous findings, strongly suggested that local structure of the amino terminus is the crucial functional determinant of TM.
Effect of microbial product made of Bacillus stearothermophilus DL-3 on microorganisms in soil and growth of lettuce and Chinese cabbage.
Journal of Life Science, volume 14, issue 5, 2004, Pages 778~787
DOI : 10.5352/JLS.2004.14.5.778
Effect of the microbial product made of Bacillus stearothermophilus DL-3, which was isolated from the soil and identified in this study, and rice bran on microorganisms in soil and growth of lettuce (Red skirt lettuce) and Chinese cabbage (Ga rack new No.1 Chinese cabbage) was investigated. Total numbers of microorganisms in the pot with untreated soil, treated with standard amount of microbial product and treated with double amounts of microbial product for growth of lettuce after 6 weeks were 2.78
CFU/g and 3.63
CFU/g. Total numbers of microorganisms in the soil without treatment of microbial product and treated with standard amount of microbial product were 2.06
CFU/g and 5.49
CFU/g. Total numbers of microorganisms in the pot with untreated soil, treated with standard amount of microbial product and treated with double amounts of microbial product for growth of Chinse cabbage after 6 weeks were 1.43
CFU/g and 7.22
CFU/g. Total numbers of microorganisms in the soil without treatment of microbial product and treated with standard amount of microbial product were 5.75
CFU/g and 7.96
CFU/g. On basis of leaf length, leaf width, leaf number, wet weight and dry weight, the growth of lettuce and Chinese cabbage on the soil treated with microbial product was faster than that on the untreated soil. The treatment of microbial product in the soil resulted in the increase of useful microorganisms, which seemed to enhance the growth of lettuce and Chinese cabbage.
Supplemented Effect of Salicornia herbacea Extract Powder on Preparation and Quality Characteristics of Fermented Milk Product.
Journal of Life Science, volume 14, issue 5, 2004, Pages 788~793
DOI : 10.5352/JLS.2004.14.5.788
Fermented milk was prepared from skim milk supplemented with Salicornia herbacea extract powder (SHEP) at the levels of 0∼0.4% (wi v) and was fermented with Lactobacillus acidophilus, Streptococcus thermophillus and Bifidobacterium longum. Quality characteristics of prepared fermented milk were evaluated for acid production, visible cell numbers, viscosity and sensory property during fermentation at 37
for 6 hr. Supplementation of 0.1% SHEP stimulated the growth of lactic acid bacteria which showed the highest number of viable cell counts (9.23 log CFU/ml), and also enhanced the acid production which was pH 4.23 and titratable acidity 0.64%, and increased the viscosity (1,365 cps) after 6 hr incubation. The sensory scores of fermented milk supplemented with 0.1% SHEP were higher than other supplemented contents in taste, texture, flavor, aftertaste and overall acceptability. When the storage abilities of fermented milk supplemented SHEP at 6
for 12 days were evaluated, its quality-keeping properties were relatively good in the fermented milk supplemented with 0.1% SHEP.
Optimization of Cyclodextrin Glucanotransferase Immobilization on Amberlite IRA-900
Seo, Hyo-Jin ; Jung, Il-Hyong ; Nam, Soo-Wan ; Kim, Byung-Woo ; Kim, Sung-Koo ;
Journal of Life Science, volume 14, issue 5, 2004, Pages 794~799
DOI : 10.5352/JLS.2004.14.5.794
Cyclodextrin glucanotransferase (CGTase) produced by Bacillus subtilis NAl/pKBl was used for the production of cyclodextrin (CD). The enzyme was purified by ion exchange and gel filtration chromatography. The purified enzyme exhibited its maximum activity in the pH range of 6.0 to 7.0 and temperature range of 60 to
. Immobilization of purified CGTase was carried out with various immobilization matrices. Amberlite IRA-900, a strong basic anion exchange resin, showed the highest immobilization ability (38 units per gram resin). Optimal pH and temperature for enzymatic reaction of the immobilized CGTase were pH 6.0 and 60t. The activity of immobilized CGTase maintained more than a month and could be reused for a month in a continuous enzyme reactor for the production of CD.
Induction of Cdk inhibitor p21 and inhibition of cyclooxygenase-2 by resveratrol in human lung carcinoma A549 cells.
Journal of Life Science, volume 14, issue 5, 2004, Pages 800~808
DOI : 10.5352/JLS.2004.14.5.800
Resveratrol, a phytoalexin found at high levels in grapes and in grape products such as red wine, has been reported to possess a wide range of biological and pharmacological activities including antioxident, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects. According to recent studies, this compound is an effective inhibitor of cell growth in general, triggers partial arrest of the cell cycle and induce apoptosis. In this study, the anti-proliferative effects of resveratrol in A549 human lung carcinoma cells were investigated. It is shown that resveratrol induced the growth inhibition in a time-dependent manner and morphological changes of A549 cells, which were associated with induction of S phase arrest of the cell cycle and apoptotic cell death. The Bcl-
levels were markedly down-regulated in resveratrol treated cells, however, Bax and Bcl-2 were remained unchanged. Resveratrol treatment induced the proteolytic degradation of Sp-l and proliferating cell nuclear antigen protein, and inhibited the expression of
-catenin protein. Resveratrol treatment also induced a marked up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21 and inhibited the kinase activities of Cdk2 and Cdk4. In addition, resveratrol treatment inhibited the levels of cyclooxygenase (COX)-2 mRNA and protein, and the release of prostagladin E2 without alteration of COX-1 expression. Taken together, these findings suggest that resveratrol may be a potential chemotherapeutic agent for the control of human lung carcinorma cells.
Effect of Electrolyzed Acidic Water on the Growth of Soybean Sprout.
Journal of Life Science, volume 14, issue 5, 2004, Pages 809~814
DOI : 10.5352/JLS.2004.14.5.809
To investigate the effect of the electrolyzed acidic water for soybean sprouts growth, the responses of characteristics of soybean sprouts were evaluated. Soybean sprouts grown by the electrolyzed acidic water showed shorter length in total body, root, and hypocotyl, etc. but they were evaluated to be increased in hypocotyl diameter and weight per sprout. Total length of soybean sprouts grown for 5 days by electrolyzed acidic water were much shorter than those by tap water. Soybean sprouts grown by tap water showed rapid growth in length even after 5 days but no more growth in length for those grown by electrolyzed acidic water. The growth of hypocotyl showed the same tendency as total length. No difference in root length among the soybean sprouts grown for 4 ~ 11 days by electrolyzed acidic water while those grown by tap water showed continuous rapid growth in length. The diameter of hypocotyl was thicker in those grown by electrolyzed acidic water than those grown by tap water and increased up 5 days. The weight of cotyledon grown by electrolyzed acidic water showed the proportional increase to the growing days but those grown by tap water showed no increase in hypocotyl weight up to 7 days, but a little bit increase after 11 days with the growth of new buds. The fresh weight per sprout was higher in those grown by electrolyzed acidic water until 7 days than tap water but it was the same weight in 11 days cultivation. The electrolyzed acidic water effected on shortening of hypocotyl and root length, thickening of hypocotyl diameter, and enlarging of cotyledon during soybean sprout cultivation.
Antitumor activity of Bacillus subtilis SW-1 isolated from Jeotgal
Journal of Life Science, volume 14, issue 5, 2004, Pages 815~820
DOI : 10.5352/JLS.2004.14.5.815
A bacterum containing antitumor activity was isolated from traditional korean food, Jeotgal. Through the 16s rRNA sequence analysis, the bacterium was identitied as a strain of Bacillus subtilis SW-l. The best culture condition for antitumor activity of the bacterium is 3% of soluble starch and 1 % of yeast extract as corbon and nitrogen sources, respectively. Cytotoxicitic concentrations of the culture supernatant of B. subtilis SW-1 against cancer cell lines, A549 and SK-OV3 were 30 ul/ml and 40 ul/ml, respectively, as
/ values. In DNA fragmentation assay, the culture supernatant showed the programmed cell death (apoptosis) to cause degrading the chromosomal DNA like ladder. Taken together, the culture supernatant of the B. subtilis SW-1 has some possibility to be used as an antitumor agent.
Identification of Quantitative Trait Loci Associated with Leaf Length. Width and Length/width Ratio in Two Recombinant Inbred Lines of Soybean (Glycine max L.)
Kim, Hyeun-Kyeung ; Kang, Sung-Taeg ;
Journal of Life Science, volume 14, issue 5, 2004, Pages 821~828
DOI : 10.5352/JLS.2004.14.5.821
The increasing apparent photosynthetic rate per leaf area may improve seed yield in soybean. Leaf area, length and width are related to the photosynthetic capability of the plant. In this study, two populations derived from the cross of Keunolkong, Shinpaldalkong and Iksanl0 were evaluated with simple sequence repeat (SSR) markers to identify length, width and length/width ratio of leaf. Leaf length/width ratio were significantly negative correlation with leaf width in K/S and K/I populations. In the K/S population, two minor QTLs for leaf length (LL) were found on LG Dlb+W and 1. Two QTLs on LG J and L were related to LL in K/I population. Two and three minor QTLs were identified in leaf width with total phenotypic variation of 13% and 18.04 in K/S and K/I populations, respectively. The leaf length/width ratio, two QTLs on LG I and L, and three QTLs on LG Cl, E and L were related to K/S and K/I populations, respectively. Thus it is assumed that the leaf traits are very much dependent on the genotype used and different breeding approach should be considered for the selection of favorite leaf traits in soybean breeding programs.
A Study on the Composition of Seasoning Using Lentinus edodes.
Journal of Life Science, volume 14, issue 5, 2004, Pages 829~833
DOI : 10.5352/JLS.2004.14.5.829
The major compositions of Lentinus edodes seasoning(LES) compose of 30.3% of Lentinus edodes fruit body, 18.1 % of anchovy (Engraulis japonicus) powder and 51.6% of sea tangle (Laminaria japonica), prawn and green tea powder and so on were investigated in order to evaluate the nutritional value. Sodium concentration in LES was high up to 5,042.99 mg/IOO g and K, Ca, P, Mg, Fe, Zn, Mn and Cu were followed. There were nineteen total amino acids in LES. The glutamic acid content was high up to 4.62 mg/100 mg and glycine, leucine, alanine, aspartic acid were followed. Among twenty free amino acids, glycine content was high up to 2.37 mg/100 mg and glutamic acid, asparanine, proline, taurin and aspartic acid were followed. The contents of vitamin C in LES was high up to 224.78 mg/100 g and pantothenic acid, vitamin B
, niacin, vitamin E, folic acid, vitamin B
, vitamin D
, vitamin A, vitamin B
The Improvement of surface activity and Emulsification Activity by Transformation of Lipase Gene in Klebsiella sp. KCL-1, Oil-Degrading Bacterium.
Journal of Life Science, volume 14, issue 5, 2004, Pages 834~839
DOI : 10.5352/JLS.2004.14.5.834
To improve and oil degrading activity, the lipase gene from Pseudomonase sp. was transformed into Klebsiella sp. KCL-l, an oil degrading bacterium. The selected trasformant was named as a KCL-1/pET-Lip. The surface tension of culture broth of KCL-1/pET-Lip was decreased to 33 dyne/cm from 55 dyne/cm using 4% (v/v) soybean oil as sole carbon source. The surface tension were 44 and 37.5 dyne/cm, to 2% (w/v) glucose and 4% (v/v) kerosene medium, respectively. The emulsification activity of the biosurfactant solution containing lipase of KCL-l/pET-Lip improved better than wild type KCL-l. The soybean oil was most efficient carbon source and substrate for surface activity and emulsification activity of KCL-1/pET-Lip. The expression of lipase was confirmed by SDS-PAGE.
Expression of Recombinant Korean Mistletoe(KM) Lectin and B genes in Saccharomyces cerevisiae
Journal of Life Science, volume 14, issue 5, 2004, Pages 840~846
DOI : 10.5352/JLS.2004.14.5.840
A study for expression of Korean Mistletoe (KM) lectin gene (A,B) in Saccharomyces cerevisiae was done using transforming system of yeast. In order to overexpress the genes efficiently in yeast, two lectin genes (A,B) were re-cloned and modified including Kozak translation initiation sequence using PCR amplification. The constructed plasmids containing modified lectin A and B genes were transformed to S. cerevisea INVSc (MAT G, his3
1, leu2, trpl-289, ura3-52). The transformed cells were identified by DNA sequencing with ABI3700 system and induced with 2% of galactose for recombinant KM lectin (rKM lectin) protein. The rKM lectin A and B proteins were determinated about 29kDa size of protein by SOS-P AGE and western blotting analysis. The expressed recombinant lectin was determinated 1.24∼1.75
per 1 mg of cytosolic soluble protein by sandwich ELISA method. Moreover the lectin genes were expressed as maximum level at 36 h after galactose induction and lectin A gene was were repressed after 48 h.
Investigation and Analysis of Allergy-related SNPs for Allergy Affected Students in a high school.
Journal of Life Science, volume 14, issue 5, 2004, Pages 847~854
DOI : 10.5352/JLS.2004.14.5.847
Allergy is a multi-factorial disease influenced by genetic and environmental factors. As the number of allergy-affected people is increasing in developed countries, there is an increasing interest in genetic predisposition to the allergy. A number of genes and chromosomal region have been identified to be linked to allergy including rhinitis, asthma and atopy. In order to understand the genetic background for the allergy-affected people, we investigated genetic predisposition among students enrolled in Busan Science Academy. Among 138 students, about 30% students had some allergy-related disorder including rhinitis, asthma and atopy. We analyzed several single nucleotide polymorphisms (SNPs) within two genes, Inter-leukin-4(IL-4) and Interleukin-4 receptor(IL-4R), which are involved in the induction of allergy reaction with the Th2 immunity. For 96 samples obtained from students, we analyzed 9 SNPs including -590 C/T and -34 C/T in IL-4, and I75V, Q576R, E375A, e406R, 5411L, S761P and S727A in IL-4R. From the analysis, these SNPs showed slight differences among normal and allergy-affected students, but these differences was not enough to predict the predisposition to the allergy. In contrast to previous reports, we could not find SNP(s) related with allergy. These results suggest that genetic tests recently performed in Korea widely have to be reassessed for its validity of genetic predisposition. [Supported by grants from MOST]
Callus induction and plant regeneration from in vitro cultured petiole of 3 Gerbera cultivars.
Journal of Life Science, volume 14, issue 5, 2004, Pages 855~858
DOI : 10.5352/JLS.2004.14.5.855
The experiment was conducted to investigate optimal condition for callus induction and plant regeneration for transformation system of gerbera. Callus induction was more effective in `white day` then other two cultivar `Songsongee` and `Love Song` The optimized plant growth regulators concentration on callus induction, was MS basal medium with NAA 0.1 mg/L＋ TDZ 0.5 mg/L. The optimized plant growth regulators concentration on plant regeneration, which was used MS basal medium was IAA 1.0 mg/L ＋ BA 1.0 mg/L ＋ Zeatin 0.1 mg/L. The optimized petiole age for more effective plant regeneration was 32 days petiole after in vitro subculture and MS basal medium strength was 1/2 MS strength.
The antifungal activity and growth promotion effects of Bacillus sp. LP03, TBM40-3 on Pohang Buchu (Leeks).
Journal of Life Science, volume 14, issue 5, 2004, Pages 859~862
DOI : 10.5352/JLS.2004.14.5.859
This report investigates antifungal activity and effects of growth promotion by biosurfactant produced from Bacillus sp. LP03 and TBM40-3 against fungus causing plants disease (Glay Mold-Botrytis cinerea). Antifugal activity against B. cinerea infeeted to leek (Allium tuberosum Rottler) exhibited better than antifungal agent farming drug (smilex, Dong bang agro., Seoul, Korea.) through the field test. After infected by plant`s disease, the leaves growth and number are maintained under presenting biosurfactant produced strains. Especially, one of the strains, named Bacillus sp. LP03 showed strong antifungal activity on field studies.
Antioxidative Effects of Pine (Pinus denstifora) Needle Extracts.
Journal of Life Science, volume 14, issue 5, 2004, Pages 863~867
DOI : 10.5352/JLS.2004.14.5.863
Antioxidative activities of pine (Pinus denstifora) needle extracts were tested in vitro experimental models. The concentration of total polyphenolic compound of water extracts from pine needle was 1.61 %. In DPPH (
-picrylhydrazyl) method, the electron donating activity of 0.1 % water extracts from pine needle was as high as BHT (0.05%, w/v). The antioxidative activity was measured by inhibition against lipid peroxidation of rat liver microsome, and this activity was shown in the following: 67.7% at 0.1% concentration >63.1% at 0.05% concentration > 28.2% at 0.01% concentration. In antioxidative activity determined by thiocyanate method against lipid peroxidation using linoleic acid, the antioxidative activities at all concentration of 0.01 %, 0.05% and 0.1 % were much higher than control during 7 days. In TBA method, the antioxidative activity was increased with increasing concentration until 6 days. These results support that water extracts from pine needle contain antioxidative compounds.
Hyperproduction of L-Threonine by Adding Sodium Citrate as Carbon Source in Transformed Escherichia coli Mutant.
Journal of Life Science, volume 14, issue 5, 2004, Pages 868~873
DOI : 10.5352/JLS.2004.14.5.868
The efficient fermentative production of L-threonine fermentation was achieved by using Escherichia coli MT201, transformed a plasmid carrying pyruvate carboxylase gene. It is an attempt to supply oxaloacetate to the L-threonine biosynthetic pathway. In order to improve the L-threonine productivity of E. coli MT201, a plasmid pPYC which is an expression vector of the pyruvate carboxylase gene of Coryne-bacterium glutamicum, was introduced. When E. coli MT/pPYC was incubated with medium containing only glucose as a carbon source, both the cell growth and L-threonine production were reduced, compared to the results from fermentation of E. coli MT201. In order to circumvent this effect, we attempted the addition of a mixed carbon source, composed of glucose and sodium citrate at a ratio of 1.5:3.5. It was shown that L-threonine production and cell growth (OD660) with E. coli MT/pPYC reached up to 75.7 g/l and 48, respectively, at incubation for 75 hr under fed-batch fermentation conditions. It is assumed that overproduction of L-threonine by anaplerotic pathway leads unbalance of TCA cycle and sodium citrate might playa role to recover normal TCA cycle.
DNA Microarray Analysis of the Gene Expression Profile of Activated Human Umbilical Vein En-dothelial Cells.
Journal of Life Science, volume 14, issue 5, 2004, Pages 874~881
DOI : 10.5352/JLS.2004.14.5.874
Angiogenesis has been implicated in progression of inflammation, arthritis, psoriasis, atherosclerosis as well as tumor growth and metastasis. Intensive studies have been carried out to develop a strategy for cancer treatment by blocking angiogenesis. During angiogenesis, endothelial proliferation and migration essentially occurs upon activation. In this study, we compared the expression profiles of human umbilical endothelial cells activated by incubating in vitro in the rich medium containing several growth factors, and non-activated ones. cDNA targets derived from total RNAs of HUVEC activated for 13 h in M199 medium containing endothelial cell growth supplement, 20% fetal bovine serum, and heparin, after reaching 70～80% confluency, or non-activated, were hybridized onto oligonucleotide microarrays containing 1,8864 genetic elements. Unsupervised hierarchical clustering analysis resulted in two subgroups on dendrogram exhibiting activated and non-activated HUVECs. We then extracted 122 outlier genes which were shown to be up-regulated or under-expressed by at least 2-folds in activated HUVECs. Among these, 32 annotated genes were up-regulated and 38 were down-regulated in activated HUVECs. Interestingly, genes involved in cell proliferation, motility, and inflammation/ immune response were up-regulated in activated HUVEC, whereas genes for cell adhesion or vessel morphogenesis/function were down-regulated. Unexpectedly, the expression of genes well-characterized as angiogenesis markers was not changed except Eph-B4, which was down-regulated about 4 folds. 52 unknown genes were also up- or down-regulated. Therefore, these results could provide an opportunity to targeting new vascular molecules for the development of anti-angiogenic molecules.
Mechanism for Gating of Gap Junction Channel.
Journal of Life Science, volume 14, issue 5, 2004, Pages 882~890
DOI : 10.5352/JLS.2004.14.5.882
Gap junction is a membrane structure facilitating the direct transmission of several ions and small molecules between two cells. It is also called an `intercellular channel` to distinguish it from other well-known cellular channels (e.g. sodium and potassium channels). Gap junction channels are not passive conduits, rather the ion channels modulated by several stimuli including pH, calcium ion, voltage, and a chemical modification (mainly known as phosphorylation). Among them, the effects of voltage on the gating of gap junction channels have been well studied. Gap junction channels are more sensitive to the transjunctional potential (
) between two cells rather than the membrane potential(
) between inside and outside the cell. In this review, I will summarize the general properties of gap junction channel and discuss the gating mechanism for the gap channels.