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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 21, Issue 12 - Dec 2011
Volume 21, Issue 11 - Nov 2011
Volume 21, Issue 10 - Oct 2011
Volume 21, Issue 9 - Sep 2011
Volume 21, Issue 8 - Aug 2011
Volume 21, Issue 7 - Jul 2011
Volume 21, Issue 6 - Jun 2011
Volume 21, Issue 5 - May 2011
Volume 21, Issue 4 - Apr 2011
Volume 21, Issue 3 - Mar 2011
Volume 21, Issue 2 - Feb 2011
Volume 21, Issue 1 - Jan 2011
Selecting the target year
Changes in Psoas Major and Quadriceps Cross Sectional Area in Elderly People after 12 Weeks of Exercise
Tachi, Toshiki ; Oguri, Kazuo ; Torii, Suguru ; Kobayashi, Kando ; Fujii, Katsunori ; Kim, Jun-Dong ; Nho, Ho-Sung ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 1~8
DOI : 10.5352/JLS.2011.21.1.1
The purpose of this study was to investigate whether 12-weeks of movement training would increase the psoas major cross-sectional area (CSA) in senior men and women. Fifty eight men and women aged 65 to 80 years old (
, 30 male, 28 female) were divided into a control (n=19) and exercise group (n=39). Subjects were assessed before and after the training program for stature, body mass, and magnetic resonance imaging of the psoas major and the quadriceps muscle. The experimental group performed exercises using machines designed to improve the movement of the hip at a frequency of twice every week, with a total of 23 trainings in 12-weeks. Magnetic resonance images of both thighs and the abdomen and psoas major were obtained, aimed at 50% of the length of the greater trochanter and the lower edge of the femur and between the fourth (L4) and fifth (L5) lumbars. A 9.4% increase in the psoas major CSA in the training group was observed. In the male and female breakdown, a 11.5% and 8.4% change was observed in males and females, respectively. In the quadriceps, there was no significant statistical improvement in either males or females. Furthermore, in the control group, there was no significant change seen in either the psoas major or the quadriceps. As a result of conducting training that enables upkeep of posture and smooth linkage of the lumbar spine, the pelvis and thighbone, the psoas major CSA of older adults were improved in a short period of time. For this reason, the possibility of improving the psoas CSA, which decreases remarkably with increased age, by improving the linkage of the body trunk is also suggested.
Gender Comparison of Ratings of Perceived Exertion (RPE) as a Predictor of Exercise Intensity in College Students
Kim, Do-Yeon ; Lee, Jeong-Ah ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 9~14
DOI : 10.5352/JLS.2011.21.1.9
Perceived exertion involves detection and interpretation of sensations arising from the body during physical exercise. Physiological variables such as heart rate and oxygen consumption positively correlate with ratings of perceived exertion (RPE). It is unknown whether the accuracy of predicting exercise intensity from RPE differs between men and women. Therefore, it was examined whether men or women could predict relative exercise intensity, determined by oxygen consumption, more accurately from RPE. Ten male and ten female young adult subjects aged 25.1
3.52 yr volunteered to participate. RPE were determined by the Borg 15-category scale, and a standard Bruce treadmill protocol was used to perform graded exercise testing. There was no significant difference in slope means between males and females (p=0.501). No significant difference was observed when plotting rates of perceived exertion (RPE) vs. percentage of
max. The relative maximal oxygen consumptions (
) were 52.36
7.35 ml/kg/min for males and 41.44
6.71 ml/kg/min for females, respectively and there was a significantly high difference between the two groups in the relative
, as well as figures of 4.05
0.36 l/min for males and 2.53
0.39 l/min for females in the absolute
in this study. There were no significant differences in slope, y-intercept, and standard error of estimate (SEE) between males and females. No significant difference with RPE according to exercise intensity was found between males and females. However, RPE was a useful predictor of exercise intensity in independent genders.
Identification and Genetic Diversity of Korean Tomato Cultivars by RAPD Markers
Huh, Man-Kyu ; Youn, Sun-Joo ; Kang, Sun-Chul ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 15~21
DOI : 10.5352/JLS.2011.21.1.15
Cultivated tomato, Lycopersicum esculentum, is a very important crop. We selected 36 cultivars and studied them for identification and polymorphism by employing random amplified DNA (RAPD) analysis with 80 oligonucleotide primers. Of the 80 primers, 36 primers (45.0%) were polymorphic. Detection of polymorphism in cultivated tomato opens up the possibility of development of its molecular map by judicious selection of genotypes. Molecular markers can also be used for cultivar identification and protection of the plant breeder's intellectual property rights (plant breeders' rights, PBRs). As an example, DNA polymorphism using OPC-13 primer that did not produce the OPC-13-01 band was only found in Junk Pink and Ailsa Craighp cultivars. OPA-12-03 and OPB-15-07 were fragments specific to the TK-70 cultivar and were absent in other cultivars. DNA polymorphism in cultivated tomato in this study was correlated with a type of inflorescence, although some cultivars had exceptions. These approaches will be useful for developing marker-assisted selection tools for genetic enhancement of the tomato plant for desirable traits.
Effects of Apolipoprotein A-I on Apoptosis and Cytokine Production in Human Neutrophils
Kang, Hyung-Kon ; Choi, Jae-Hyung ; Huh, Jae-Taeck ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 22~30
DOI : 10.5352/JLS.2011.21.1.22
Apolipoprotein A-I (apoA-I) has anti-inflammatory and anti-oxidative properties. This study was designed to investigate whether apoA-I affects apoptosis and cytokine production of human blood neutrophils in an in vitro culture system. Spontaneous apoptosis of neutrophils was significantly delayed by apoA-I. In addition, high density lipoprotein containing apoA-I also delayed apoptosis of neutrophils. Apoptosis of neutrophils was inhibited by anti-scavenger receptor type B-I antibodies. The amounts of interleukin-8, interferon (IFN)-inducible protein 10 (IP-10), and tumor necrosis factor-
) in the supernatants of cultured neutrophils treated with apoA-I were significantly increased. Combined treatment of neutrophils with IFN-
and apoA-I produced higher amounts of IP-10 and TNF-
than did treatment with IFN-
or apoA-I alone. The present study reveals that apoA-I activates neutrophils to produce cytokines and delays spontaneous apoptosis of neutrophils. These findings suggest that apoA-I, although a well-known negative acute-phase protein, has a pro-inflammatory effect in neutrophils.
Characterization of a Dual-Specificity Protein Phosphatase, Human DUSP28
Jeong, Dae-Gwin ; Kim, Song-Yi ; Yun, Jeong-Hun ; Kim, Jae-Hoon ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 31~35
DOI : 10.5352/JLS.2011.21.1.31
Dual-specificity protein phosphatases (DUSPs) constitute a family of protein phosphatase characterized by the ability to dephosphorylate phospho-tyrosyl and phospho-seryl/threonyl residues. Most DUSPs are involved in regulation of cell survival and differentiation. In this study, a human dual-specificity protein phosphatase, DUSP28, was isolated from a human kidney cDNA. The recombinant protein was successfully produed in E.coli and showed sufficient phosphatase activity toward DiFMUP (6,8-difluoro-4-methylumbelliferyl phosphate). Various phosphatase inhibitors and divalent metals were tested for their effects on the DUSP28 phosphatase activity. As a result,
was found to strongly inhibit DUSP28 phosphatase activity, suggesting DUSP28 is involved in Zn-related signal transduction pathway. Furthermore, the DUSP28 protein preferred phospho-tyrosyl residues to phospho-threonyl residues, implying its physiological roles in the cellular process.
Glycated Serum Albumin Induces Interleukin-6 Expression in Vascular Smooth Muscle Cells
Baek, Seung-Il ; Rhim, Byung-Yong ; Kim, Koan-Hoi ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 36~43
DOI : 10.5352/JLS.2011.21.1.36
Diabetes mellitus is associated with vascular complications. Diabetic patients exhibit high levels of glycated adducts in serum compared to non-diabetic individuals. The aim of this study was to investigate whether extracellular glycated albumin (GA) predisposes vascular smooth muscle cells (VSMCs) to pro-inflammatory phenotype. Exposure of rat aortic smooth muscle cells (AoSMCs) to GA not only enhanced interleukin-6 (IL-6) release but also activated promoter activity of the IL-6 gene. GA-induced IL-6 promoter activation was suppressed by dominant-negative forms of Toll-like receptor (TLR)-4 and myeloid differentiation factor 88 (MyD88), but not by dominant-negative-forms of TLR-2 and TIR-domain-containing adapter-inducing interferon-
(TRIF). Extracellular signal-regulated kinase (ERK) inhibition and diphenyleneiodium (DPI) also attenuated IL-6 induction by GA. Mutation at the nuclear factor-
)-binding site in the IL-6 promoter region suppressed promoter activation in response to GA. The present study proposes that GA would contribute to inflammatory reaction in the stressed vasculature by inducing IL-6 in VSMCs, and that TLR-4, EKR, and NF-
play active roles in the process.
Extract of Rubus coreanus Fruits Increases Expression and Activity of Endothelial Nitric Oxide Synthase in the Human Umbilical Vein Endothelial Cells
Yoon, Hyun-Joong ; Park, Soo-Young ; Oh, Sung-Tack ; Lee, Kee-Young ; Yang, Sung-Yeul ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 44~55
DOI : 10.5352/JLS.2011.21.1.44
This study aimed to investigate the effects of water extract of Rubus coreanus (RCE) on the expression and activity of endothelial nitric oxide synthase (eNOS), as well as its signal transduction pathways in human umbilical vein endothelial cells (HUVECs). The specific inhibitors of NOS show RCE treatment increases NO production in HUVECs due to the up-regulation of eNOS rather than iNOS. The real-time expression level of eNOS mRNA was also increased upon RCE treatment in HUVECs. While a PKC-specific inhibitor, RO-317549, did not alter RCE-induced NO production in HUVECs, tamoxifen (estrogen receptor-specific inhibitor), PD98059 (ERK-specific inhibitor) and LY-294002 (PI3K/Akt-specific inhibitor) did have suppressive effects. Increased NO production by RCE seems to result from a higher level of active eNOS (pSer1177). Specifically, inhibition of ERK not only decreased the level of active eNOS, but also increased the inactive form of the enzyme (pThr495) in HUVECs. This study suggests that RCE treatment increases NO production in HUVECs due to the increased expression and activity of eNOS. It is also shown that RCE-induced eNOS activation occurs partly through the binding of RCE to the estrogen receptor, along with ERK and PI3K/Akt-dependent signal transduction pathways. In addition, the regulatory binding proteins of eNOS including Hsp90 and caveolin-1 were related to these effects of RCE on eNOS activity in HUVECs.
Antioxidant Activities of Ostrich Fern by Different Extraction Methods and Solvents
Shin, So-Lim ; Lee, Cheol-Hee ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 56~61
DOI : 10.5352/JLS.2011.21.1.56
This study was performed to investigate effective extract conditions in fronds of the Ostrich fern (Matteuccia struthiopteris) to increase antioxidant compound contents and antioxidant capacity. Powder (1 g) of lyophilizated fronds were mixed with 3 kinds of solvents (MeOH, 80% EtOH and water). Extractions were carried out using not only immersion (room temp.), heating (
) and stirring (200rpm) for 6 hr, but also through sonication in a 42 kHz ultrasonic bath for 15, 30 and 45 min. Extracts were filtrated and measured for contents of soluble solids (SS), total polyphenols (TP; tannic acid as a standard) and total flavonoids (TF; Naringin as a standard). Antioxidant activity was expressed as
for DPPH and ABTS radical scavenging. SS (0.317
db), TP (70.90
db) and TF (41.53
db) contents reached their highest levels when 30 minute sonication extraction with 80% EtOH was performed, and the highest DPPH and ABTS scavenging activity was observed in the same extraction conditions (
, respectively). From the present investigation, it can be concluded that fronds of the ostrich fern can be used as a natural material for antioxidants, and sonication for 15-30 min with 80% EtOH is an ideal extraction method for increasing their antioxidant effects and saving extraction time.
Antioxidant Activity and Alpha-Glucosidase Inhibitory Activity of Stings of Gleditsia sinensis Extracts
Lee, Jeung-Min ; Park, Jae-Hee ; Chu, Won-Mi ; Yoon, Yi-Mook ; Park, Eun-Ju ; Park, Hae-Ryong ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 62~67
DOI : 10.5352/JLS.2011.21.1.62
This study was performed to investigate the physiological activities of stings of Gleditsia sinensis extracts. Antioxidant activity was evaluated by measuring total phenolic contents (TPC), comet assay, and 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA). Anti-diabetic activity was measured by inhibition activities on
-glucosidase. Stings of Gleditsia sinensis extracts were prepared by extracting them with methanol and ethanol. The methanolic extracts showed the highest phenol content (1.12 g/100 g gallic acid equivalents). The
-glucosidase inhibitory activity of methanol extracts were 17.9% higher, and that of ethanol extracts were 10.3% higher at a concentration of 1 mg/ml. These results indicate that stings of Gleditsia sinensis might be potential candidates as antioxidant and anti-diabetic agents.
Application of β-1,3-Glucanase from Pyrococcus furiosus for Ethanol Production using Laminarin
Kim, Dong-Gyun ; Kim, Eun-Young ; Kim, Yu-Ri ; Kim, Joong-Kyun ; Lee, Han-Seung ; Kong, In-Soo ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 68~73
DOI : 10.5352/JLS.2011.21.1.68
-1,3-glucanase from Pyrococcus furiosus was applied for the saccharification of laminarin, which is a major oligo-saccharide component of brown algae, and the reaction mixture produced from laminarin was utilized as a substrate for alcohol fermentation using yeast. To prepare the recombinant
-1,3-glucanase gene was overexpressed in Escherichia coli and purified. Laminarin was degraded to an oligo- and mono-saccharide, such as glucose, after reaction with the purified recombinant
-1,3-glucanase, and the products after enzymatic treatment were confirmed by TLC and HPLC analysis. Decomposed laminarin after enzyme reaction was only added to the medium as a C-source for yeast alcohol production reaction. 0.3% alcohol production was detected from the cultured broth by gas chromatography after 48 hr of incubation. Further evaluation for optimal conditions of saccharification and alcohol fermentation can be suggested, as well as the possibility of using this enzymatic method to produce ethanol using laminarin.
Quality Characteristics and Free Amino Acid Content of Seasoning Pork Meat Aged by Red Wine
Park, Kyung-Suk ; Lee, Kyung-Soo ; Park, Hyun-Sook ; Choi, Young-Jun ; Kang, Se-Ju ; Yang, Jong-Beom ; Hyon, Jae-Seok ; Jung, In-Chul ; Moon, Yoon-Hee ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 74~80
DOI : 10.5352/JLS.2011.21.1.74
This study was carried out to investigate the effects of the addition of red wine on the quality characteristics and free amino acid content of seasoned pork meat. Seasoned pork meat was prepared using three variation: pork meat containing 25% water (T0), pork meat containing a combination of 20% water and 5% red wine (T1), pork meat containing a combination of 15% water and 10% red wine (T2), and pork meat containing a combination of 10% water and 15% red wine (T3). There were no significant differences in moisture, crude protein, crude fat, crude ash, a* value, rheological properties, pH, VBN content, saturated fatty acid or unsaturated fatty acid among T0, T1, T2 and T3. The L* and b* value of seasoned pork meat was higher in T2 and T3 than in T0 and T1 (p<0.05). The TBARS value was highest in T0 (p<0.05). The free amino acid content was higher in T2 and T3 than in T0 (p<0.05).
Biological Activity and Biochemical Properties of Silkworm (Bombyx mori L.) Powder Fermented with Bacillus subtilis and Aspergillus kawachii
Cha, Jae-Young ; Kim, Yong-Soon ; Ahn, Hee-Young ; Kang, Min-Jung ; Heo, Su-Jin ; Cho, Young-Su ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 81~88
DOI : 10.5352/JLS.2011.21.1.81
Biological activities (
-picrylhydrazyl (DPPH) free radical scavenging activity, fibrinolytic activity and reducing power) and biochemical properties (protein content and electrophoretical protein patterns) were examined in solid state fermentation with Bacillus subtilis and Aspergillus kawachii using silkworm powder (SP) as substrate. The highest protein contents and free radical scavenging activities were seen in the SP fermented for 12 days with B. subtilis and A. kawachii, and these were in a time-dependent manner. The highest reducing power was seen in the SP fermented for 6 days with B. subtilis and for 12 days with A. kawachii, respectively. The highest fibrinolytic activities were seen in silkworm fermented for 6 days with B. subtilis and A. kawachii, but this activity was higher in the A. kawachii fermented SP than that of B. subtilis. When total protein patterns were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE), the proteins of the SP fermented with B. subtilis for 3 days were completely degraded, while the protein degradation in the SP fermented with A. kawachii occurred after 12 days and this degradation increased proportionally to culture time. As a result, the SP fermented with both B. subtilis and A. kawachii showed higher fibrinolytic activities after 6 days of fermentation and antioxidative activity after 12 days, indicating that physiological activities of the fermented SP using these strains were highly improved compared to the unfermented SP, and that this compound could be a candidate material as a dietary supplement of healthy functional foods.
Apoptotic Effects of Curcumin and EGCG via Akt-p53 Signaling Pathway in HCT116 Colon Cancer Cells
Park, Song-Yi ; Lee, Sol-Hwa ; Park, Ock-Jin ; Kim, Young-Min ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 89~95
DOI : 10.5352/JLS.2011.21.1.89
p53 is tumor suppressor gene that regulates apoptosis such as caspase-dependent and p21-mediated signaling pathways. PI3K/Akt is known to be over-activated in cancer cells. Akt activates many survival-related signals such as mTOR and COX-2. Inactivation of Akt would result in non-inhibition of p53 as well as induced apoptosis. In this study, we showed that curcumin and EGCG activate p53 via inhibition of the Akt signaling pathway. Treatments using curcumin and EGCG in different concentrations for 24 hr and 48 hr inhibited proliferation of HCT116 colon cancer cells and increased apoptotic cell death. Also, our data showed that curcumin and EGCG increased the p53 expression and decreased the p-Akt. Treatment of LY294002 (Akt inhibitor) resulted in decreased cell proliferation of cancer cells, while LY294002 treated with curcumin or EGCG showed a greater decrease of cell proliferation. In addition, inhibition of Akt induced p53 activation in HCT116 colon cancer cells. These results suggest that curcumin and EGCG induce apoptosis by inhibiting Akt and increase p53 in HCT116 colon cancer cells.
Cloning and Functional Analysis of Gene Coding for S-Adenosyl-L-Methionine Synthetase from Streptomyces natalensis
Yoo, Dong-Min ; Hwang, Yong-Il ; Choi, Sun-Uk ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 96~101
DOI : 10.5352/JLS.2011.21.1.96
S-Adenosyl-L-methionine synthtase (SAM-s) catalyzes the biosynthesis of SAM from ATP and L-methionine. SAM plays important roles in the primary and secondary metabolism of cells. A metK encoding a SAM-s was searched from Streptomyces natalensis producing natamycin, a predominantly a strong antifungal agent, inhibiting the growth of both yeasts and molds and preventing the formation of aflatoxin in filamentous fungi. To obtain the metK of S. natalensis, PCR using primers designed from the two highly conserved regions for metK genes of Streptomyces strains was carried out, and an intact 1.2-kb metK gene of S. natalensis was cloned by genomic Southern hybridization with PCR product as a probe. To identify the function of the cloned metK gene, it was inserted into pSET152ET for its high expression in the Streptomyces strain, and then introduced into S. lividans TK24 as a host by transconjugation using E. coli ET12567(pUZ8002). The high expression of metK in S. lividans TK24 induced actinorhodin production on R5 solid medium, and its amount in R4 liquid medium was 10-fold higher than that by exconjugant including only pSET152ET.
Distribution Pattern of Inhibitory and Excitatory Nerve Terminals in the Rat Genioglossus Motoneurons
Moon, Yong-Suk ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 102~109
DOI : 10.5352/JLS.2011.21.1.102
The genioglossus muscle plays an important role in maintaining upper airway patency during inspiration; if this muscle does not contract normally, breathing disorders occur due to closing of the upper airway. These occur because of disorders of synaptic input to the genioglossus motoneurons, however, little is known about it. In this study, the distribution of GABA-, glycine-, and glutamate-like immunoreactivity in axon terminals on dendrites of the rat genioglossus motoneurons, stained intracellularly with horseradish peroxidase (HRP), was examined by using postembedding immunogold histochemistry in serial ultrathin sections. The motoneurons were divided into four compartments: the soma, and primary (Pd), intermediate (Id), and distal dendrites (Dd). Quantitative analysis of 157, 188, 181, and 96 boutons synapsing on 3 soma, 14 Pd, 35 Id, and 28 Dd, respectively, was performed. 71.9% of the total number of studied boutons had immunoreactivity for at least one of the three amino acids. 32.8% of the total number of studied boutons were immunopositive for GABA and/or glycine and 39.1% for glutamate. Among the former, 14.2% showed glycine immunoreactivity only and 13.3% were immunoreactive to both glycine and GABA. The remainder (5.3%) showed immunoreactivity for GABA only. Most boutons immunoreactive to inhibitory amino acids contained a mixture of flattened, oval, and round synaptic vesicles. Most boutons immunoreactive to excitatory amino acids contained clear and spherical synaptic vesicles with a few dense-cored vesicles. When comparisons of the inhibitory and excitatory boutons were made between the soma and three dendritic segments, the proportion of the inhibitory to the excitatory boutons was high in the Dd (23.9% vs. 43.8%) but somewhat low in the soma (35.7% vs. 38.2%), Pd (34.6% vs. 37.8%) and Id (33.1% vs. 38.7%). The percentage of synaptic covering of the inhibitory synaptic boutons decreased in the order of soma, Pd, Id, and Dd, but this trend was not applicable to the excitatory boutons. The present study provides possible evidence that the spatial distribution patterns of inhibitory and excitatory synapses are different in the soma and dendritic tree of the rat genioglussus motoneurons.
Effects of Dietary Mugwort (Artemisia iwayomogi Kitamura) Powder Supplementation on Growing Performance in Pig
Ha, Im-Jung ; Jeong, Mi-Ae ; Kim, Byung-Uk ; Kim, Jong-Duk ; Ryu, Yeon-Sun ; Kim, Sam-Woong ; Lee, Chul-Young ; Jung, Ki-Hwa ; Cho, Kwang-Keun ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 110~118
DOI : 10.5352/JLS.2011.21.1.110
This study was conducted to investigate growth performance in weanling and growing pigs supplemented with mugwort powder as an antibiotic replacement. To examine the effects of antibiotic replacement, 0 (control, with and without antibiotics), 1, and 1.5% mugwort powder was supplemented into the basal diet. Pigs raised with a diet of 1.0% mugwort powder had improved average daily gain and feed conversion rate during 23~37 d feeding. During 40~59 and 63~97 d feeding periods, there were no differences between average daily gain in pigs fed no antibiotics and those given a 1% mugwort powder diet, whereas feed conversion rate of pigs given a 1.5% mugwort powder diet and average daily gain of pigs fed no antibiotics were lower than those of any other diet group. In conclusion, this study suggests that the 1.0% supplementation of mugwort in place of antibiotics is an invaluable feed additive as a physiologically activated material.
Overexpression and Activity Analysis of Cystathionine γ-Lyase Responsible for the Biogenesis of H
Kim, Kyoung-Ran ; Byun, Hae-Jung ; Cho, Hyun-Nam ; Kim, Jung-Hyun ; Yang, Seun-Ah ; Jhee, Kwang-Hwan ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 119~126
DOI : 10.5352/JLS.2011.21.1.119
There is a growing recognition of the significance of
as a biological signaling molecule involved in vascular and nervous system functions. In mammals, two enzymes in the transsulfuration pathway, cystathionine
-synthase (CBS) and cystathionine
-lyase (CGL), are believed to be chiefly responsible for
biogenesis. Genetic inborn error of CGL leads to human genetic disease, cystathioninuria, by accumulating cystathionine in the body. This disease is secondarily associated with a wide range of diseases including diabetes insipidus and Down's syndrome. Although the human CGL (hCGL) overexpression is essential for the investigation of its function, structure, reaction specificity, substrate specificity, and protein-protein interactions, there is no clear report concerning optimum overexpression conditions. In this study, we report a detailed analysis of the overexpression conditions of the hCGL using a bacterial system. Maximum overexpression was obtained in conditions of low culture temperature after inducer addition, performing low aeration during overexpression, and using a low concentration inducer (0.1 mM, IPTG) for induction. Expressed hCGL was purified by His-tag affinity column chromatography and confirmed by Western blot using hCGL antibody and enzyme activity analysis. We also report that the His tag with TEV site attached protein exhibits 76% activity for
elimination reaction with L-cystathionine and 88% for
elimination reaction with L-cysteine compared to those of wild type hCGL, respectively. His tag with TEV site attached protein also exhibits a 420 nm absorption maximum, which is attributed to the binding cofactor, pyridoxal 5'-phosphate (PLP).
Characteristics of Lactose Hydrolysis by Immobilized β-Galactosidase on Chitosan Bead
Kang, Byung-Chul ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 127~133
DOI : 10.5352/JLS.2011.21.1.127
-Galactosidase was immobilized on chitosan bead by covalent bonding using glutaraldehyde. The characteristics of the immobilized enzyme were investigated. Maximum immobilization yield of 75% was obtained on chitosan bead. Optimum pH and temperature for the immobilized enzyme was 7.0 and
, respectively. The immobilized enzyme showed a broader range of pH and temperature compared to a free one. A mathematical model for the operation of the immobilized enzyme in a packed-bed reactor was established and solved numerically. Under different inlet lactose concentrations and feed flow rate conditions, lactose conversion was measured in a packed-bed reactor. The experimental results of continuous operation in a packed-bed reactor were compared to theoretic results using Michaelis-Menten kinetics with competitive product inhibition and external mass transfer resistance. The model predicted the experimental data with errors less than 5%. Process optimization of continuous operation in a packed-bed reactor was also conducted. In a recirculation packed-bed operation, conversion of lactose was 97% in 3 hours. In a continuous packed-bed operation, the effect of flow rate and initial lactose concentration was investigated. Increasing flow rates and initial lactose concentration decreased the conversion of substrate.
Characteristics of Biosurfactant Producing Pseudomonas sp. Z1
Chang, Dong-Ho ; Ko, Eun-Jung ; Park, Kyeong-Ryang ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 134~140
DOI : 10.5352/JLS.2011.21.1.134
One hundred forty five bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in the Daejon area. Among these colonies, one bacterial strain was selected for this study based on its low surface tension ability, and this selected bacterial strain was identified as Pseudomonas sp. Z1 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. Z1 showed a high resistance to antibiotics such as chloramphenicol and ampicillin, as well as heavy metals such as lithium, manganese, and barium. It was found that the optimal pH and temperature for biosurfactant production of Pseudomonas sp Z1 were pH 6.0-7.0 and
, respectively. After ten hours of inoculation, the biosurfactant activity of the culture broth decreased rapidly, and had maximum surface tension (28 dyne/cm) after twenty-one hours incubation. The biosurfactant activity of the culture broth was also decreased up to 2% NaCl concentration.
Actinomycin D Induces Phosphorylation of STAT3 through Down-Regulation of SOCS3 in Renal Cancer Cells
Woo, Seon-Min ; Park, Eun-Jung ; Kwon, Taeg-Kyu ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 141~145
DOI : 10.5352/JLS.2011.21.1.141
Actinomycin D is a natural antibiotic that is used in anti-cancer chemotherapy and is known as a transcription inhibitor. Interestingly, actinomycin D induces phosphorylation of signal transducers and activators of transcription 3 (STAT3) in renal cancer Caki cells. In this study, we examined the molecular mechanism of actinomycin D-induced STAT3 phosphorylation. Treatment with actinomycin D induced phosphorylation of STAT3 (Tyr705) in a dose- and time-dependent manner. However, actinomycin D did not induce phosphorylation of STAT3 (Ser727), STAT1 (Tyr701) and STAT1 (Ser727). Moreover, actinomycin D-induced STAT3 phosphorylation was caused by decreased protein and mRNA levels of SOCS3, but not by JAK2 and SHP-1. In addition, other transcription inhibitor (5,6-dichloro-1-b-D-ribofuranosyl benzimidazole; DRB) also induced phosphorylation of STAT3 (Tyr705). Taken together, the present study demonstrates that transcriptional inhibitors (actinomycin D and DRB) induce phosphorylation of STAT3 (Tyr705) in Caki cells by down-regulation of SOCS3.
Physiological Changes of Saccharomyces cerevisiae KNU5377 Occurred in the Process of the 48-hour Ethanol Fermentation at 40℃
Kwak, Sun-Hye ; Kim, Il-Sup ; Kang, Kyung-Hee ; Lee, Jung-Sook ; Jin, Ingn-Yol ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 146~154
DOI : 10.5352/JLS.2011.21.1.146
In this study, physiological changes in a thermotolerant yeast Saccharomyces cerevisiae KNU5377 cell exposed to 48-hour alcohol fermentation at
were investigated. After 12 hours of alcohol fermentation at
unsaturated acid of plasma membrane increased to 1.5 times more than the
saturated fatty acid, and to about 2 times more for the
unsaturated fatty acid. Fermentation at both
fermentation showed the same pattern as that done at
. The pH of the alcohol-fermentation medium was reduced to pH 4.1 from a starting pH of 6.0 through the 12-hr fermentation and then maintained this level during the continuing fermentation. With the process of fermentation, the remaining glucose was reduced, but its amount remaining during the
-fermentation was less reduced than those fermented at
. In the study investigating the changing pattern of cellular proteins in the alcohol-fermenting cells, the SDS-PAGE and 2-D data indicated the most expressed dot was phosphoglycerate kinase, which is one enzyme involved in glycolysis. Why this enzyme was most expressed in the cells exposed to unfavorable conditions such as high temperature, increasing concentration of produced alcohol and long time exposure to other stress factors remains unsolved.
Association of a Single Nucleotide Polymorphism with Economic Traits in Porcine Uncoupling Protein 3 Gene
Oh, Jae-Don ; Lee, Kun-Woo ; Jung, Il-Jung ; Jeon, Gwang-Joo ; Lee, Hak-Kyo ; Kong, Hong-Sik ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 155~158
DOI : 10.5352/JLS.2011.21.1.155
Uncoupling protein (UCP) 3 has a number of proposed roles in the regulation of fatty acid metabolism. A number of polymorphisms in the human UCP3 gene have been identified, and the correlation with obesity related phenotypes evaluated. The objective of this study was to identify SNP in porcine UCP3 gene and to investigate the effect of the SNP on economic traits. The sequencing analysis method was used to identify nucleotide polymorphisms at position 1405 bp (Genebank accession No : AY739704) in porcine UCP3 gene. The SNP (G150R), located in the exon 3, changed the amino acid to glycine (GGG) from arginine (AGG). This G150R showed three genotypes - GG, GR and RR - by digestion with the restriction enzyme Sma Ⅰ using the PCR-RFLP method. The G150R showed significant effects only on back fat (P<0.05). Animals with the genotype GG had significantly higher back fat thickness (1.358 cm) than animals with the genotype GR (1.288 cm, P<0.05) and RR (1.286 cm, P<0.05). However, the genotypes had no significant association with ADG and days to 90kg. According to results of this study, a G allele of the G150R was found to have a significant effect on back fat thickness. It will be possible to use SNP markers on selected pigs to improve backfat thickness, an important economic trait.
Applications of Microbial Whole-Cell Biosensors in Detection of Specific Environmental Pollutants
Shin, Hae-Ja ;
Journal of Life Science, volume 21, issue 1, 2011, Pages 159~164
DOI : 10.5352/JLS.2011.21.1.159
Microbial whole-cell biosensors can be excellent analytical tools for monitoring environmental pollutants. They are constructed by fusing reporter genes (e.g., lux, gfp or lacZ) to inducible regulatory genes which are responsive to the relevant pollutants, such as aromatic hydrocarbons and heavy metals. A large spectrum of microbial biosensors has been developed using recombinant DNA technology and applied in fields as diverse as environmental monitoring, medicine, food processing, agriculture, and defense. Furthermore, their sensitivity and target range could be improved by modification of regulatory genes. Recently, microbial biosensor cells have been immobilized on chips, optic fibers, and other platforms of high-throughput cell arrays. This paper reviews recent advances and future trends of genetically modified microbial biosensors used for monitoring of specific environmental pollutants.