• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.136-141
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• 1989

A raw starch-digesting enzyme from Streptomyces sp. 4M-2 was purified by ammonium sulfate fractionation, DEAE-Sephadex A-50 column chromatography and Sephadex G-100 gel filtration. The specific activity of the purified enzyme was 51.22 RSU/mg protein and the yield was 4.5% of the total activity of the culture broth. The purified enzyme was found to be homogeneous by polyacrylamide gel electrophoresis and its molecular weight was estimated to be about 102, 000 daltons by SDS-polyacrylamide gel electrophoresis, The optimal temperature and pH for the enzyme activity were 42$^{\circ}C$ and PH 5.5, respectively. The enzyme had Km, value of 44.44mg/$m\ell$ for raw corn starch. The enzyme was activated by addition of calcium and barium ions. Corn amylose was degraded by the enzyme very easily and raw potato starch was also degraded easily. Main products of the enzymatic hydrolysis of raw corn starch were analyzed to be maltose and maltotriose. The enzyme was considered as $\alpha$-amylase.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.239-244
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• 1987

Low molecular weight plant ribonucleic acids including potato spindle tuber viroid(PSTV) RNA were electrophoresed in 0M to 8M urea-gradient polyacrylamide gels. The electrophoresis was carried on in a urea - gradient gel system with 1/40 and 1/10 dilution of TBE buffer at three different temperatures, $17^{\circ}C,\;37^{\circ}C\;and\;57^{\circ}C$. The most effective separation of PSTV - RNA molecules into circular and linear forms was achieved at the highly denaturing temperature of $57^{\circ}C$ and at 1/40 dilution of TBE buffer. The electrophoretic mobility of the denatured circular viroid-RNA molecules is dependent mainly on the concentration of urea. In addition, a low concentration of TBE buffer would increase the separation distance between the circular and linear forms of PSTV-RNA molecules in the denaturing urea-gradient gel system

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.409-416
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• 1992

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus were $15^{\circ}C$ and 72 hrs, respectively. The addition of casein, nutrient broth and egg albumin to the basal medium, respectively, increased greatly the enzyme production. The enzyme was purified by ammonium sulfate fractionation, CM-cellulose and DEAE-cellulose column chromatographies. The specific activity of the purified enzyme was 29.09 U/mg protein and the yield of enzyme activity was 17.1% The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and its molecular weight was estimated to be 61,000 by SDSpolyacrylamide disc gel electrophoresis. The isoelectric point for the purified enzyme was pH 7.0. The optimum temperature and pH were $40^{\circ}C$ and 6.5. The purified enzyme was stable below $35^{\circ}C$ and in the pH range of 6.5-11.0. It was greatly inhibited by $Ag^{+}$, $Hg^{2+}$ and $Zn^{2+}$, and its thermal stability was increased by the addition of $Ca^{2+}$ Among various substrates, pullulan was favorably hydrolyzed by the purified enzyme and the hydrolysis product 011 pulluIan was maltotriose.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.88-91
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• 1985

For the systematic investigation of biochemical characteristics of Korean ginseng protein, protein fractions were analyzed by the techniques of sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The effect of pH and various salts on extractibility of ginseng protein were determined while the amino acid composition was studied by amino acid autoanalyzer. The protein was consisted of 66.08% of albumin and 20.51% of glutelin. Extractability of ginseng protein was the lowest in pH 3.0 and the highest in $pH\;6.0{\sim}8.0$. Among the neutral salts solution, $0.4M\;Na_2CO_3$ showed maximum extractability while $1.0M\;MgSO_4$ solution showed the least extractability. Resonable precipitation was obtained by 40% of acetone and ammonium sulfate. It has been shown by SDS polyacrylamide gel electrophoresis that the soluble protein had 11 bands. The molecular weight for the main protein of the soluble protein wasestimated to be 43,000. In amino acid composition of water extracted protein, arginine content was the highest 47.17% while on the contray, proline and cystine contents were very low.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.180-183
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• 1987

Stu I, type II restriction endonuclease, has been purified to homogeneity from Streptomyces tubercidicus (ATCC 25502), and its catalytic properties have been studied. For the purification of Stu I endonuclease free of nonspecific nucleases, DEAE-Sephadex (A-50), QAE-Sephadex (A-50) and Heparin-agarose column chromatography have been performed after ammonium sulfate fractionation of the crude extract. The enzyme was further purified by gel filtration using Sephadex G-100 column to obtain homogeneous form of protein. The single polypeptide species of Stu I endonuclease has a subunit molecular weight of 34,000 $\pm$ 1,000 daltons as judged by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Stu I endonuclease requires $Mg^{2+}$ ion for its activity and is maximally active at neutral pH (7.0-8.0) in the absence of NaCl.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.129-133
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• 1997

A total 943 accession of soybeans (G. max) and 50 wild soybeans (G. soja) were examined for leucine aminopeptidase (LAP) isozyme variation by 5％ polyacrylamide gel electrophoresis(PAGE) and isoelectric focusing(IEF) of pH 4~6.5. The Lap1*b by PAGE was the most common phenotype in both G. max and G. soja. The frequency of Lap1*b allele was observed to be higher in G. max(1.00) than in G. soja(0.96) of Korea. This result shows that G. max is fixed for Lapl*b allele at the Lap1 locus. LAP isozyme band type I and II were found using IEF of pH 4~6.5 in G. max and G. soja of Korea. Type I was observed from 92.8％ in G. max and 92.0％ in G. soja, and type II was discovered in 7.2％ G. max and 8.0％ G. soja. This result suggested the possibility to be found more various band types.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.387-394
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• 1983

The factor, which was capable of accelerating the yeast cell wall lysis of the zymolyase(${\beta}-1$, 3-glucanase), was purified to a homogeneous state from the protease fraction of the crude zymolyase by Sephadex G-75 gel filtration and preparative polyacrylamide gel disc electrophoresis. The molecular weight of the purified factor was estimated to be 40,500 by SDS-polylacrylamide gel disc electrophoresis and it's iso-electric point was pH 9.6. The factor was found to be a basic protease consisted of single polypeptide chain with 395 amino acid residues and it showed the $E_{280,cm}^{1%}$ of 11.9 and the molecular extinction coefficient of $4.83{\times}10^4$, respectively.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1902-1906
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• 2010

A microchip electrophoresis (ME) method was developed using a programmed field strength gradients (PFSG) for the single nucleotide polymorphism (SNP) based fast identification of cattle breeds. Four different Korean cattle (Hanwoo) and Holstein SNP markers amplified by allele-specific polymerase chain reaction were separated in a glass microchip filled with 0.5% poly(ethyleneoxide) ($M_r$ = 8 000 000) by PFSG as follows: 750 V/cm for 0 - 14 s, 166.7 V/cm for 14 - 31 s, 83.3 V/cm for 31 - 46 s, and 750 V/cm for 46 - 100 s. The cattle breeds were clearly distinguished within 45 s. The ME-PFSG method was 7 times and 5 times faster than the constant electric field ME method and the capillary electrophoresis- PFSG method, respectively, with a high resolving power ($R_s$ = 5.05 - 9.98). The proposed methodology could be a powerful tool for the fast and simultaneous determination of SNP markers for various cattle breeds with high accuracy.

• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.126-130
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• 2007

Noroviruses, members of the family Caliciviridae, are often found in shellfish grown in polluted water and are emerging as a leading cause of foodborne disease worldwide. As the presence of norovirus in food commodities becomes an important medical and social issue, there are increasing needs for designing improved detection methods for the virus. In this study, we tested the Agilent 2100 Bioanalyzer for the analysis of norovirus DNA amplified from oyster samples. Microchip electrophoresis provided us with more accurate information, compared to conventional agarose gel electrophoresis, in the resolution and quantification of amplified products. The development of an improved method for food-associated noroviruses would contribute to a rapid identification of contaminated food and improve our understanding of the modes of food contamination and norovirus transmission.

• The Plant Pathology Journal
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• v.40 no.1
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• pp.40-47
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• 2024

Garlic can be infected by a variety of viruses, but mixed infections with leek yellow stripe virus, onion yellow dwarf virus, and allexiviruses are the most damaging, so an easy, inexpensive on-site method to simultaneously detect at least these three viruses with a certain degree of accuracy is needed to produce virus-free plants. The most common laboratory method for diagnosis is multiplex reverse transcription polymerase chain reaction (RT-PCR). However, allexiviruses are highly diverse even within the same species, making it difficult to design universal PCR primers for all garlic-growing regions in the world. To solve this problem, we developed an inexpensive on-site detection system for the three garlic viruses that uses a commercial mobile PCR device and a compact electrophoresis system with a blue light. In this system, virus-specific bands generated by electrophoresis can be identified by eye in real time because the PCR products are labeled with a fluorescent dye, FITC. Because the electrophoresis step might eventually be replaced with a lateral flow assay (LFA), we also demonstrated that a uniplex LFA can be used for virus detection; however, multiplexing and a significant cost reduction are needed before it can be used for on-site detection.