• BMB Reports
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• v.38 no.2
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• pp.177-181
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• 2005

Effects of common electrophoretic reagents, reducing agents ($\beta$-mercaptoethanol [BME] and DTT), denaturants (SDS and urea), and non-ionic detergent (Triton X-100), on the activity and stability of bovine plasmin (b-pln) and human plasmin (h-pln) were compared. In the presence of 0.1% SDS (w/v), all reagents completely inhibited two plns, whereas SDS (1%) and urea (1 M) denatured plns recovered their activities after removal of SDS by treatment of 2.5% Triton X-100 (v/v). However, reducing agents (0.1 M of BME and DTT) treated plns did not restore their activities. Based on a fibrin zymogram gel, five (from b-pln) and four (from h-pln) active fragments were resolved. Two plns exhibited unusual stability in concentrated SDS and Triton X-100 (final 10%) and urea (final 6 M) solutions. Two bands, heavy chain-2 (HC-2) and cleaved heavy chain-2 (CHC-2), of b-pln were completely inhibited in 0.5% SDS or 3 M urea, whereas no significant difference was found in h-pln. Interestingly, 50 kDa (cleaved heavy chain-1, CHC-1) of b-pln and two fragments, 26 kDa (light chain, LC) and 29 kDa (microplasmin, MP), of h-pln were increased by SDS in a concentration dependent manner. We also found that the inhibition of SDS against both plns was reversible.

• Journal of Ocean Engineering and Technology
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• v.5 no.2
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• pp.207-207
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• 1991

The crack length measurements by electrical potential(EP) method for 1% Cr-Mo-V and 12%Cr steel of 0.5T-CT specimen were performed at $500^{\circ}C, 600^{\circ}C 700^{\circ}C$, and an applicability of stress intensity factor($K_I$), net section stress($\sigma_{net}$), $C^*$-ingegral and $C_t$ parameter was studied to measure creep crack growth rate(da/dt) with side groove and without side groove under static and cyclic loading condition. The experimental result could be summarized as follows: 1) Crack measurement by EP method was available and coincided with the Johnson,s analytical equation. 2) da/dt by $K_I$ and $\sigma_{net}$ was not adequate because of the wide scatter band according to load and temperature, but $C^*$-integral, except for transition region, was adequate. 3) $C_t$ parameter showed the best fitted line through total creep region without relating with both temperature and load condition. 4) Under the cyclic loading condition, $C_t$ parameter was proper to extimate da/dt. And it was shown that da/dt for 1% Cr-Mo V steel under the static condition(R=1) was 1.16 times faster than the case under cyclic loading(R=0), and for 12% Cr steel, 1.43 times.

• Journal of Ocean Engineering and Technology
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• v.5 no.2
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• pp.67-75
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• 1991

The crack length measurements by electrical potential(EP) method for 1% Cr-Mo-V and 12%Cr steel of 0.5T-CT specimen were performed at $500^{\circ}C, 600^{\circ}C 700^{\circ}C$, and an applicability of stress intensity factor($K_I$), net section stress($\sigma_{net}$), $C^*$-ingegral and $C_t$ parameter was studied to measure creep crack growth rate(da/dt) with side groove and without side groove under static and cyclic loading condition. The experimental result could be summarized as follows: 1) Crack measurement by EP method was available and coincided with the Johnson, s analytical equation. 2) da/dt by $K_I$ and $\sigma_{net}$ was not adequate because of the wide scatter band according to load and temperature, but $C^*$-integral, except for transition region, was adequate. 3) $C_t$ parameter showed the best fitted line through total creep region without relating with both temperature and load condition. 4) Under the cyclic loading condition, $C_t$ parameter was proper to extimate da/dt. And it was shown that da/dt for 1% Cr-Mo V steel under the static condition(R=1) was 1.16 times faster than the case under cyclic loading(R=0), and for 12% Cr steel, 1.43 times.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.127-130
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• 2004

Grapevine leaf roll-associated virus 3 (GLRaV-3) is one of the most important viral diseases of grapevine in the world. In this study, GLRaV-3 Ampelovirus was identi-fied from grapevines in Korea by analyzing viral coat protein size, nucleotide, and amino acid sequences. The molecular weight of viral coat protein from virus-infected in vitro plantlets was determined by western blot using a commercial GLRaV-3 polyclonal antibody. Western blot analysis showed a coat protein of about 43 kDa. RT-PCR product of about 942 bp which encoded the coat protein (CP) gene was amplified with specific primers. When the viruses existed at low titers in the host plant, the dsRNA had very specific template in RT- PCR amplification of fruit tree viruses. Especially, small-scale dsRNA extraction method was very reliable and rapid. Sequence analysis revealed that the CP of the GLRaV-3 Ko consisted of 942 bp nucleotide, which encoded 314 amino acid residues. The CP gene of GLRaV-3 Ko had 98.9% nucleotide sequence and 98.7% amino acid sequence identities with earlier reported GLRaV-3. This is the first report on molecular assay of GLRaV-3 Ampelovirus identified from Korea. The GLRaV-3 Ko CP clone would be very useful for breeding of virus resistant grapevines.

• Restorative Dentistry and Endodontics
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• v.42 no.2
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• pp.87-94
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• 2017

Objectives: Chitosan has been widely investigated and used. However, the literature does not refer to the shelf life of this solution. This study evaluated, through the colorimetric titration technique and an analysis of dentin micro-hardness, the shelf life of 0.2% chitosan solution. Materials and Methods: Thirty human canines were sectioned, and specimens were obtained from the second and third slices, from cemento-enamel junction to the apex. A 0.2% chitosan solution was prepared and distributed in 3 identical glass bottles (v1, v2, and v3) and 3 plastic bottles (p1, p2, and p3). At 0, 7, 15, 30, 45, 60, 90, 120, 150, and 180 days, the specimens were immersed in each solution for 5 minutes (n = 3 each). The chelating effect of the solution was assessed by micro-hardness and colorimetric analysis of the dentin specimens. 17% EDTA and distilled water were used as controls. Data were analyzed statistically by two-way and Tukey-Kramer multiple comparison (${\alpha}=0.05$). Results: There was no statistically significant difference among the solutions with respect to the study time (p = 0.113) and micro-hardness/time interaction (p = 0.329). Chitosan solutions and EDTA reduced the micro-hardness in a similar manner and differed significantly from the control group (p < 0.001). Chitosan solutions chelated calcium ions throughout the entire experiment. Conclusions: Regardless of the storage form, chitosan demonstrates a chelating property for a minimum period of 6 months.

• Korean Journal of Environmental Agriculture
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• v.38 no.2
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• pp.104-109
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• 2019

BACKGROUND: The invasive hornet Vespa velutina nigrithorax has becomes a public concern in rural and urban South Korea. The technologies are necessary to develop a way to counter V. velutina. In an effort to develop a way to counter V. velutina, we found that a bacillus strain, named Bacillus sp. BV-1, produces volatile compounds that attract V. velutina. METHODS AND RESULTS: Field trials of V. velutina attraction were performed using plates and traps containing BV-1 cultures grown on sugar medium. When the sugar medium and sugar-grown BV-1 cultures in the plates were placed close together, V. velutina visited preferably the plates with the BV-1 cultures. Significantly more V. velutina were caught in the traps containing BV-1 cultures than in those containing only sugar medium. Headspace solid-phase microextraction coupled with GC/MS analysis of BV-1 cultures detected 2-methyl-1-propanol, 3-methyl-1-butanol, 3-methylbutanoic acid, ethyl hexanoate, 2-pheylethanol, ethyl octanoate, and ethyl decanoate as the major volatiles. CONCLUSION: BV-1 cultures were suggested as potential agents for managing V. velutina as they produce volatile compounds that attract the hornet.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.26-32
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• 2000

Catechol 2,3-dioxygenase was purified from recombinant strain E. coli CNU312 carrying the tomB gene which was cloned from toluene-degrading Burkholderia cepacia G4. The purification of this enzyme was performed by acetone precipitation, Sephadex G-75 chromatography, electrophoresis and electro-elution. The molecular weight of native enzyme was about 140.4 kDa and its subunit was estimated to be 35 kDa by SDS-PAGE. It means that this enzyme consists of four identical subunits. This enzyme was specifically active to catechol, and$K_(m)$ value and $V_(max)$value of this enzyme were 372.6 $\mu$M and 39.27 U/mg. This enzyme was weakly active to 3-methylcatechol, 4-methylcatechol, and 4-chlorocatechol, but rarely active to 2,3-DHBP. The optimal pH and temperature of the enzyme were pH 8.0 and $40^{\circ}C$. The enzyme was inhibited by $Co^(2+)$, $Mn^(2+)$, $Zn^(2+)$, $Fe^(2+)$, $Fe^(3+)$, and $Cu^(2+)$ ions, and was inactivated by adding the reagents such as N-bromosuccinimide, and $\rho$-diazobenzene sulfonic acid. The activity of catechol 2,3-dioxygenase was not stabilized by 10% concentration of organic solvents such as acetone, ethanol, isopropyl alcohol, ethyl acetate, and acetic acid, and by reducing agents such as 2-mercaptoethanol, dithiothreitol, and ascorbic acid. The enzyme was inactivated by the oxidizing agent $H_(2)$$O_(2)$, and by chelators such as EDTA, and ο-phenanthroline.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.235-241
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• 2023

Noroviruses are a major cause of gastroenteritis in humans and animals worldwide. In 2021, canine norovirus (CNoV) infection was detected at an animal clinic in Gwangju area, South Korea. A semi-nested polymerase chain reaction was developed to amplify a 478 bp fragment of the RdRp gene of CNoV. The phylogenetic analysis of this fragment confirmed the strain to be genogroup IV.2 (Dog/GIV.2/gw/s377/2021/KOR), which exhibited the highest similarity to the feline NoV strain GIV.2/CU081210E/USA/2010 (accession no. NC_045762) with 95.1% nucleotide (nt) identity and 98.7% amino acid (aa) identity. These research findings indicate that the detected norovirus in dogs is genetically similar to a feline-origin norovirus, suggesting easy cross-species transmission among animals.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1321-1324
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• 2012

Background: DNA polymerase beta ($pol{\beta}$) is a key enzyme in the base excision repair pathway. It is 39kDa protein, with two subunits, one large subunit of 31 kDa having catalytic activity between exon V to exon XIV, and an 8 kDa smaller subunit having single strand DNA binding activity. Exons V to VII have double strand DNA binding activity, whereas exons VIII to XI account for the nucleotidyl transferase activity and exons XII to XIV the dNTP selection activity. Aim: To examine the association between $pol{\beta}$ polymorphisms and the risk of ovarian cancer, the present case control study was performed using 152 cancer samples and non-metastatic normal samples from the same patients. In this study, mutational analysis of $pol{\beta}$ genomic DNA was undertaken using primers from exons IX to XIV - the portion having catalytic activity. Results: We detected alteration in DNA polymerase beta by SSCP. Two specific heterozygous point mutations of $pol{\beta}$ were identified in Exon 9:486, A->C (polymorphism 1; 11.18%) and in Exon 11:676, A->C (polymorphism 2; 9.86%). The correlation study involving polymorphism 1 and 4 types of tissue showed a significant correlation between mucinous type with a Pearson correlation value of 4.03 (p=0.04). The association among polymorphism 2 with serous type and stage IV together have shown Pearson ${\chi}^2$ value of 3.28 with likelihood ratio of 4.4 (p=0.07) with OR =2.08 (0.3-14.55). This indicates that there is a tendency of correlation among polymorphism 2, serous type and stage IV, indicating a risk factor for ovarian cancer. Conclusion: Hence, the results indicate that there is a tendency for $pol{\beta}$ polymorphisms being a risk factor for ovarian carcinogenesis in India.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.55-58
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• 2008

Alanine racemase, a bacterial enzyme belonging to the fold-type III group of pyridoxal 5'-phosphate (PLP)-dependent enzymes, has been shown to catalyze the interconversion between L- and D-alanine. The alanine racemase from the pathogenic bacterium Enterococcus faecalis v583 has been overexpressed in E. coli and was shown to crystallize an enzyme at 295 K, using polyethylene glycol (PEG) 8000 as a precipitant. X-ray diffraction data to $2.5{\AA}$ has been collected using synchrotron radiation. The crystal is a member of the orthorhombic space group, $C222_1$ with unit cell parameter of a=94.634, b=156.516, $c=147.878{\AA},\;and\;{\alpha}={\beta}={\gamma}=90{\AA}$. Two or three monomers are likely to be present in the asymmetric unit, with a corresponding $V_m\; of\;3.38{\AA}^3\;Da^{-1}\;and\;2.26{\AA}^3\;Da^{-1}$ and a solvent content of 63.7% and 45.5%, respectively.