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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 10, Issue 6 - Dec 2000
Volume 10, Issue 5 - Oct 2000
Volume 10, Issue 4 - Aug 2000
Volume 10, Issue 3 - Jun 2000
Volume 10, Issue 2 - Apr 2000
Volume 10, Issue 1 - Feb 2000
Selecting the target year
Separation of Tetrodotoxin, DHA and EPA from Pufferfish Liver Waste
Journal of Life Science, volume 10, issue 2, 2000, Pages 115~124
The present study was undertaken to separate the available components effectively, such as tetrodotoxin(TTX), docosahexaenoic acid(DHA, C22:6,ω-3) and eicosapentaenoic acid (EPA, C20:5,ω -3) from pufferfish liver waste, which are known to have high values as bioactive materials. By using ultrafiltration, it was possible to separate high contents of 68mg TTX from pufferfish liver waste. In contrast, by activated charcoal column, it was to obtain about 54mg TTX. The recovering ratios were 65.3% and 45.0% in the two different methods of ultrafiltration and activated charcoal column, respectively. From the results of HPLC and gas chromatography-mass spectrometry(GC-MS), the obtained toxins were identified to be TTX and its derivatives. In addition, it was also possible to obtain 72.3g DHA and 11.4g EPA from 1kg of pufferfish liver by high performance liquid chromatography (HPLC). These amounts of DHA and EPA were also 17.70% and 1.04% in the total lipid of pufferfish liver oil from analysis of gas chromatography(GC), respectively.
Overexpression and Secretory Production of Endoxylanase from Recombinant Bacillus subtilis
Journal of Life Science, volume 10, issue 2, 2000, Pages 125~130
To overproduce endoxylanase from a recombinant Bacillus subtilis harboring the pJHKJ4 plasmid, the effects of carbon and nitrogen sources on the cell growth and expression level of endoxylanase were investigated in the flask cultures. Among the various carbon and nitrogen sources tested, glucose and maltose as carbon source and yeast extract as nitrogen source were found to be the most effective for the cell growth and the endoxylanase expression. When the concentration of glucose was increased from 0.5% to 5%, the highest activity of extracellular endoxylanse, 166 unit/
, was observed at 2% glucose. In case of maltose, the endoxylanase was stably produced at the level of 180 unit/
, regardless of the concentration of maltose. The higher the concentration of yeast extract, the greater cell growth and endoxylanase expression were obtained. However, the highest endoxylanase activity per unit cell mass was observed with 1% yeast extract. With the optimized medium (2% glucose, 1% yeast extract, etc), about 630 unit/
of endoxylanse was expressed through the batch fermentation in a fermentor, which expression level corresponded to about 0.7 g-endoxylanase protein /
. It was also found that the plasmid was stably maintained above 70% level, and more than 90% of endoxylanase activity was detected in the extracellular medium.
Antioxidative Effect of Enzymatic Protein Hydrolysate from Lecithin-Free Egg Yolk
Journal of Life Science, volume 10, issue 2, 2000, Pages 131~139
Lecithin-free egg yolk protein (EYP), the by-product of lecithin extraction from egg yolk, which is denatured with an organic solvent, would normally be discarded. In this study, the denatured protein was renatured with alkali, and hydrolyzed with Alcalase in order to utilize by-product. The hydrolysate was separated through a series of ultrafiltration membranes with molecular weight cut-off (MWOO) of 10, 5 and 1 kDa, and the antioxidative activities of the hydrolysates was investigated. The 5K hydrolysate, permeate from 5 kDa membrane, showed stronger antioxidative activity than 10 K and 1 K hydrolysate which were permeated from 10 kDa and 1 kDa membrane, in a linoleic acid autoxidation system. In addition, the optimum concentration of antioxidative activity for 5 K hydrolysate was 1%, and the activity was about 37% higher as compared with α-tocopherol. The synergistic effect was also increased by using the hydrolysates with α-tocopherol.
Purification and Characterization of Angiotensin I Converting Enzyme lnhibitory Peptides from Enzymatic Hydrolysate of Cod Liver Protein
Journal of Life Science, volume 10, issue 2, 2000, Pages 140~149
In order to utilize marine processing waste which would normally be discarded, cod liver protein was hydrolysed by
-chymotrysin, and the hydrolysate was investigated for the new angiotensin I converting enzyme (ACE) inhibitor. Thy hydrolysate was separated into three major types, with molecular weight cut-off (MWCO) values less than 10 kDa, 5 kDa and 1 kDa of ultrafiltration membranes, respectively. ACE inhibitory peptides were isolated from the fractions passed through MWCO 1 kDa membrane, and purified by using ion-exchange chromatography on a SP-Sephadex C-25 column, gel filtration on a Sephadex G-15 column, and HPLC on an ODS column. The purity was identified with capillary electrophoresis. The amino acid sequences of two peptides were Met-Ile-Pro-Pro-Tyr-Tyr (IC50=10.9
M) and Gly-Leu-Arg-Asn-Gly-Ile (IC50=35.0
A Gene Encoding Endoplasmic Reticulum Resident 29 kDa Protein is Regulated by TSH-Dependently at the Transcription Level
Journal of Life Science, volume 10, issue 2, 2000, Pages 150~156
This experiment was performed to evaluate the effect of TSH (thyroid-stimulating) on the ERp29 (endoplasmic reticulum resident 29 kDa protein) gene expression in the rat thyrocytes of FRTL-5 cells. Although ERp29 mRNA was constantly expressed, its expression began to increase remarkably from 10-9 M TSH. and its maximum expression was at 5×10-9 M TSH (about 3.5 fold). On the other hand, the effect of TSH on the abundance of ERp29 mRNA started within 6 h, and peaked at 8 h (about 2.5 fold). Actinomycin D (transcription inhibitor) strongly blocked this effect while cycloheximide (translation inhibitor) did not. The half-life of ERp29 mRNA was about 4.5 h in the presence or absence of TSH that was not affected by the stability of ERp29 mRNA. The effect of TSH on the ERp29 gene expression was specific, while other growth factors (transfferin, insulin, and hydrocortisone) did not alter its expression. Our data indicate for the first time that the expression of ERp29 is regulated transcriptionally by TSH in the thyrocytes.
Biological and serological characteristics of Pseudomonas aeruginosa from clinical specimens
Journal of Life Science, volume 10, issue 2, 2000, Pages 157~163
One hundred eight strains of Pseudomonas aeruginosa isolated from the patients (sputum, urine, burn skin, stool and blood) of Pusan National University hospital were tested for exonezyme production, antimicrobial susceptibility and serotyping. The results obtained were as follow: In exonezyme production test, 50 strains (46.30%) produced both protease and elastase. Thirty three strains (30.55%) did not produce any exoenzyme, 18 strains (16.67%) produced only protease and 7(6.48%) stains only produced elastase. As the result of antimicrobial susceptibility by the disc diffusion method, most strains were resistant to sulfamethoxazole (96.30%). But the resistant rate against gentamicin and ticarcillin were 47.23% and 46.30% respectively. The resistant rate to other antibiotics were less than 40%. All strains could be serologically typed. Most strains were identified as type Ⅲ: among them, 51 strains were belonged to serotype E. The correlation of serotype and exoenzyme production was not found.
Ecological Characteristics and Insecticidal Susceptibility of Sycamore Lace Bug, Corythucha ciliata Say (Hemiptera: Tingidae)
Journal of Life Science, volume 10, issue 2, 2000, Pages 164~168
To understand the biological characteristics of Corythucha ciliata occurring in Korea, developmental periods and its susceptibility to several insecticides were examined under growth chamber condition at
. It took 11.1 day from egg to hatch. And duration of each stage up to the 5th nymph after hatching was 4.0, 2.1, 2.0, 2.9, and 4.0 days, respectively. Total duration from egg to adult was 26.1 days, preoviposition period was 12.2 days, and average number of eggs laid by a female was 83.0. Sex ratio of female was 51.6% and lifespan of female adult was 43.2% days. LC50 value of deltamethrin and esfenvalerate were 0.8 and 0.9 ppm, respectively. Insecticidal effects were better in pyrethroids than organophosphates and carbamates.
Community Composition and Adapted Environment of Sundew (Drosera rotundifolia) in Koppler Moor, Austria
Journal of Life Science, volume 10, issue 2, 2000, Pages 169~176
At Koppl area, undamaged natural habitat of sundew, I have analysed interspecific affinities and community composition through mathematical method and important environmental factors. Interspecific affinities of the species with frequency of more than 5% in vegetation table were analysed through chi-square test and showed obvious group of Drosera rotundifolia, Vaccinium uliginosum, Calluna vulgaris, Eriophorum angustifolium and 21 species. The result of ordination anlysis using DECORANA of VESPAN II showed eigenvalue of 0.6047 for axis I, 0.2024 for axis II and 0.0763 for axis Ⅲ. And it divided into 4 groups of quadrat number 1-5 for Sphagnum squarrosum-community, 6-10 for Crepis paludosa-community. 11-25 for Carex panicea-community and 26-35 for Scorpidium scorpioides-community. By the classification using TWINSPAN, the 7 areas divided into 2 groups of 1-10 and 11-35 at first level of division with high eigenvalue of 0.588 and indicator was Sphagnum squarrosum. At second level of division it divided into 4 groups as the results of DECORANA with eigenvalues of 0.268 and 0.423 and indicators were Pinguicula vulgaris and Scorpidium scorpioides. Microclimatic environment of studied area was low in temperature and high in humidity and soil environment showed high in field moisture capacity, acid, high organic matter content, low NO3 and K2O content, compare to normal soil, and high ground water level.
Combining Ability and Correlation for Some Quantitative Characters of F2 Hybrids in Barley
Journal of Life Science, volume 10, issue 2, 2000, Pages 177~181
This study was conducted to estimate the genetic parameters such as combining ability, heritabilities and correlation coefficients forsome agronomic characters by 6
6 dialled crosses of barley. The results obtained were summarized as follows. Mean squares of general combining ability(GCA) and specific combining ability(SCA) were significant for all characters observed. Mean squares of general combining ability for all characters were expressed as higher values than those of specific combining ability. Jecheon #5 showed the high general combining ability effects for culm length, and Waegwanpimack #1 showed the highest general combining ability effects for tiller number. Cygne also showed the high general combining ability effects for spike length and 1,000 grains weight. Furthermore, Plumage was expressed with the highest general combining ability effects for spike length and 1,000 grains weight. Furthermore, Plumage was expressed with the highest general combining ability effects for number of grains per spike. In specific combining ability effects, Samdugjeonbug # 45
Plumage showed the high value for culm length, and Suwon #6
was expressed with the highest specific combining ability effects for tiller number. Jecheon #5
Plumage also showed the high specific combining ability effects for spike length and number of grains per spike. Suwon #6
Cygne showed the high specific combining ability effects for 1,000 grains weight. The heritabilities of spike length an number of grains per spike were over 90%. In correlation coefficients among characters, relationships between culm length and tiller number, culm length and spike length, culm length and 1,000 grains weight, and spike length and 1,000 grains weight showed highly positively correlation.
Optimization of RAPD-PCR Conditions for Onions, Allium cepa L.
Journal of Life Science, volume 10, issue 2, 2000, Pages 182~187
The optimized RAPD-PCR conditions, which can be utilized as a basic information for the analysis of the genetic characteristics were investigated with four onion varieties, named Changryungdaego, Yeoeuijuhwang, Yakwangju, and Dabonghwang using Operon primers, OPR01 (TGCGGGTCCT) and OPZ20 (ACTTTGGCGG). We tested several concentrations of DNA, primer, and MgCl2, annealing temperature, number of PCR cycle, and presence/absence of pre-heating time at the begining of PCR reation in the 25
volume. The best RAPD profiles were obtained using 50ng of DNA, 5mM of primer, 1.5mM of MgCl2, 45
of annealing temperature and an absence of pre-heating time. An establishment of the stable and reproducible RAPD-PCR conditions are expected to be useful for the subsequent RAPD-related investigation, such as genetic characterization of the onion strains, re-establishment of phylogenetic relationships and development of new varieties.
Analysis of Expressed Sequence Tags Generated from the Posterior Silkgland cDNA Clones of Antheraea yamamai
Journal of Life Science, volume 10, issue 2, 2000, Pages 188~195
In order to understand molecular events during silk synthesis and provide genetic resources for molecular breeding, we had analyzed the cDNA library constructed from the posterior silkgland of Antheraea yamamai and partially sequenced 276 randomly selected genes from the cDNA library. Database comparisons of the expressed sequence tags (ESTs) revealed that 26 non-redundant clones showed a high similarity with previously identified genes. Among them, 17 clones exhibited a homology with previously identified insect genes and 9 clones were identical to genes that were previously identified from other organisms. A functional categorization showed that silk synthesis-defense- or stress-related genes, as well as genes involved in the metabolic pathways and in the transcriptional or translational apparatus are represented. In this report, the clone (AY479) which had high similarity with fibroin from A. pernyi was particularly analyzed in detail. The AY479 clone was carboxyl terminal region of fibroin. The 472 bp cDNA has 123 amino acids that shared 85% homology with the fibroin from A. pernyi and its deduced peptide had unique feature, that is, sites of alanine rich residues.
Production of Tetrodotoxin Using Novel Marine Microorganism Isolated from Intestine of Pufferfish
Journal of Life Science, volume 10, issue 2, 2000, Pages 196~201
The production of tetrodotoxin (TTX) using Vibrio sp. YE-101, a novel marine microorganism isolated from the intestine of pufferfish, was investigated. Culture condition was optimized for the enhanced production of TTX using response surface methodology. The experimental sets of environmental conditions including pH, temperature and NaCl concentration were designed using central composite experimental design. The optimal conditions of pH, temperature and NaCl concentration were determined to be 8.1, 29.2℃, and 2.6% (w/v) respectively. The relative growth extent could be enhanced up to 80%, and final mouse unit (MU) value of TTX was also enhanced up to 87% by response surface optimization.
Changes in Chemical Compositions of Green Tea (Camellia sinensis L) under the Different Extraction Conditions
Journal of Life Science, volume 10, issue 2, 2000, Pages 202~209
The factors affecting chemical composition of green tea (Camellia sinensis L.) during extraction process were temperatures and times. The optimum extraction conditions were measured in relation to the changes of chemical compositions from water extracts of green tea (Camellia sinensis L.) under different extraction temperatures (50, 70, 9
) and extraction times (1, 3, 5 minute). The change of color intensity during browning reaction, flavonoid components, contents of total phenols and hydrogen donating activity (reducing activity for
-picryhydrazyl) of water extracts form green tea increased as extraction temperatures increased from 50 to 9
and extraction times prolonged from 1 to 5 min. The contents of important free sugars such as sucrose and glucose slightly increased as the extraction time was prolonged, while little difference in the content of fructose with the prolonged extraction time. Catechins contents extracted from the commercial steamed green tea were increased at higher temperature and longer extraction time. Epigallocatechin (EGC) extracted from 9
(extraction time 5 min). presented 99.9 mg/g in highest composition of catechin followed by epigallocatechin gallate (EGCg), epicatechin (EC), epicatechin gallate (ECg). The content of vitamin C extracted from green tea was increased about 2 times as the extraction temperature increased from 50 to 9
and as the extraction time increased from 1 to 5 min. with exception at 9
(extraction time:5 min) which showed less vitamin C content than 7
(extraction time : 3 min) probably due to possible destruction of vitamin C by high temperature.
Distinctive pH Dependence and Substrate Specificity of Peptide Hydrolysis by Human Stromelysin-1
;Marianne V. Sorensen;
Journal of Life Science, volume 10, issue 2, 2000, Pages 210~217
A kinetic profile of the catalytic domain of stromelysin-1 (SCD) using the fluorescent peptide substrate has been determined by the stopped-flow technique. The pH profile has a pH optimum of about 5.5 with an extended shoulder above pH 7. Three pKa values, 5.0, 5.7, and 9.8 are found for the free enzyme state and two pH independent Kcat/Km values of 4.1
104 M-1 s-1 and 1.4
104 M-1 s-1 at low and high pH, respectively. The profile is quite different in shape with other MMP family which has been reported, having broad pH optimum with two pKa values. The substrate specificity of SCD towards fluorescent heptapeptide substrates has been also examined by thin layer chromatography. The cleavage sites of the substrates have been identified using reverse-phase HPLC method.SCD cleaves Dns-PLA↓L↓WAR and Dns-PLA↓L↓FAR at two positions. However, the Dns-PLA↓LRAR, Dns-PLE↓LFAR, adn Dns-PLSar↓LFAR are cleaved exclusively at one bond. The double cleavages of Dns-PLALWAR and Dns-PLALFAR by SCD are in marked contrast to the close structurally related matrilysin. A notable feature of SCD catalysis agrees with the structural data that the S1' pocket of SCD is deeper than that of matriysin. The differences observed between SCD and matrilysin may form the basis of understanding the structural relationships and substrate specificities of the MMP family in vivo.
Expression, Refolding, and Characterization of the Proteolytic Domain of Human Bone Morphogenetic Protein 1
Journal of Life Science, volume 10, issue 2, 2000, Pages 218~227
Bone morphogenetic protein 1 (BMP-1) is part of a complex capable of inducing ectopic bone formation in mammals. Studies on TGF-β1 processing and Drosophila dorsal-ventral patterning have focused attention on BMP-1 as important in mediating the biological activity of this bone inducing complex. Herein, the bacterial expression, refolding, purification, and initial characterization of the BMP-1 proteolytic domain (BPD) are described. A semi-quantitative fluorescence-based thin layer chromatography assay was developed to assist in rapidly screening for optimal renaturation conditions. According to a preliminary screen for optimal conditions for the refolding of BPD , a detectable proteolytic activity against a high turnover substrate for astacin, a homologous protease from crayfish was observed. The conditions identified have allowed the expression of sufficient amounts of BPD for the characterization of the protein. Its proteolytic activity exhibits the same cleavage specificity as astacin against seven substrates that were previously synthesized for studying astacin. Furthermore, this activity is inhibited by the metal chelator 1,10-phenanthroline but not by its analogue 1,7-phenanthroline. The collagenase inhibitor Pro-Leu-Gly hydroxamate was found to inhibit both astacin and BPD activity. The results presented in this paper argue that BMP-1 does in fact possess an intrinsic proteolytic activity.