• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1749-1759
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• 2018

Recombinant (rec) prion protein (PrP) is an extremely useful resource for studying protein misfolding and subsequent protein aggregation events. Here, we report mass production of high-purity rec-polypeptide encoding the C-terminal globular domain of PrP; (90-230) for human and (89-231) for murine PrP. These proteins were expressed as His-tagged fusion proteins in E. coli cultured by a high cell-density aerobic fermentation method. RecPrPs recovered from inclusion bodies were slowly refolded under reducing conditions. Purification was performed by a sequence of metal-affinity, cation-exchange, and reverse-phase chromatography. The current procedure yielded several dozens of milligrams of recPrP per liter with >95% purity. The purified recPrPs predominantly adopted an ${\alpha}$-helix-rich conformation and were functionally sufficient as substrates to measure the seeding activity of human and animal prions. Establishment of a procedure for high-level production of high-purity recPrP supports the advancement of in vitro investigations of PrP including diagnosis for prion diseases.

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.247-265
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• 1998

To determine the sequence and expression of the VP7 gene of Korean isolates (CAU-9), viral RNA was purified and used for cDNA amplification by RT-PCR. The VP7 cDNA was cloned, sequenced, and expressed using baculovirus expression system. The result showed that the sequence homologies CAU-9 compared with foreign isolated strains Wa, 417, TMC-II, 95B and SA11 were ranged from 74.0% to 95.1 % of nucleotide sequence and 35% to 43% of amino acid sequence, respectively. High homology of CAU-9 was observed in Japanease isolates 417 (nucleotide sequence homology was 95.1% and amino acid sequence homology was 43%). To express VP7 gene, the VP7 cDNA was cloned into pCR-Bac vector and inserted into the genome of baculovirus adjacent to the polyhedrin promoter by cotransfection of Spodoptera frugiperda (Sf9) insect cells with wild type baculovirus DNA. In antigenic analysis of Sf9 cells inoculated with the recombinant VP7, immunofluorescence assay revealed positive for viral antigens. In metabolic labeling of Sf9 cell lysates infected with recombinant baculoviruses, it was revealed that the protein of 34 kDa was expressed. The limited study of expressed VP7 protein inoculated with guinea pigs failed to elicit neutalizing antibody. As a results, the sequence analysis and expression of VP7 protein of rotavirus CAU-9 isolated from an infant in Korea could permit the conformation and development of virus like particles which may be useful in designing vaccine strategy.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.891-898
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• 2005

The trunk and limb of the Jindo, Korean native dog was measured in the present study. One hundred and ninety five Jindoes were randomly selected from the 1,985 dogs in the Jindo County in August 1998, which were screened by the judging committee of the County and registered by inserting electronic chips in the withers. They were about a year and half old, and were white and fawn dogs. A total of 18 parts of the trunk and limb were measured using calipers and tapes. The average height at the withers was 50.67 cm in dogs and 47.48 cm in bitches. The average body length was 52.99 cm in dogs and 50.33 cm in bitches. And the average height : body length ratio was 104.70 in dogs and 106.08 in bitches. No differences were observed between the Jindoes of the two coat colors in these measurements. The results of this study would be useful for compiling the official standard for the adult Jindo.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.325-330
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• 2006

The head of the Jindo, Korean native dog was measured in the present study. One hundred and ninety five Jindoes were randomly selected from the 1,985 dogs in the Jindo County in August 1998, which were screened by the judging committee of the County and registered by inserting electronic chips in the withers. They were about one and a half-year-old, and were white and fawn dogs. The head was divided into three parts; the skull, ear and nose. Each part was divided again, and a total of 14 parts of the head were measured using calipers. Measurements of the skull part and skull index were bigger in dogs than in bitches, but no differences were found between sexes. No differences were found in the measurements of the ear part between sexes or coat colors, except the distance between two ears in which the distance was longer in dogs than in bitches. In the measurements of the nose, the width of rostral part was larger in fawns than in whites and in dogs than in bitches. The rest were larger in dogs than in bitches.

• Journal of Animal Science and Technology
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• v.51 no.2
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• pp.97-104
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• 2009

Complement of test standard, evaluation methods and models are needed to improve national competitiveness and to exchange superior genetic resources through the comparison of genetic evaluation score among nations in dairy cattle. Therefore, this study was conducted for the application of international standard to Korea considering domestic circumstance by changing linear-classification test score system of 50 classes which is currently used in Korea to system of 9 classes which is used in advanced nations of dairy. 15,230 of holstein cow linear type records with first parity records for the fifteen linear type and one total score from 2001 to 2006 and pedigree data which were collected by the Korean Animal Improvement Association were used in this study. Population classified by 9 levels was more normal distributed than 50 levels. Correlation coefficients between 50 and 9 score system showed over 0.98 by each classification scheme. Therefore, the 50 point system can be substituted with 9 point system due to their highly positive correlation. However, scores in all traits were still very contingent on classifier under the 9 point system (p<0.001), and F values between foot angle and front teat attachment showed high fluctuation depending on classifier. It means that subjective opinions of classifier would influence on linear type score as ever even if class scheme transformed to system of 9 class. Therefore, the relevance of transformation to the 9 point system should be assessed after analyses about various environmental factors.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.475-482
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• 2007

The thermal and optical properties of glucose penta(cholesteryloxycarbonyl)alkanoates (CAGLn, n = 2~8, 10, the number of methylene units in the spacer) were investigated. All the CAGLn formed monotropic cholesteric phases with left-handed helical structures. CAGLn with n = 2 or 10, in contrast with CAGLn with $3{\leq}n{\leq}8$, did not display reflection colors over the full cholesteric range, suggesting that the helical twisting power of the cholesteryl group highly depends on the length of the spacer joining the cholesteryl group to the glucose chain. The isotropic-cholesteric transition point ($T_{ic}$) decreased with increasing n and showed no odd-even effect. The plot of transition entropy at $T_{ic}$ against n had a sharp negative inflection at n = 7. The optical pitches (${{\lambda}_m}^{\prime}$ s) of CAGLn with $3{\leq}n{\leq}8$ decreased with increasing temperature. However, the temperature dependence of the ${\lambda}_m$ of the derivatives exhibited pronounced dependence on n. The transitional properties and the temperature dependence of the ${\lambda}_m$ observed for CAGLn were discussed in terms of the differences in arrangement of the cholesteryl groups and the conformation of the molecules.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.163-167
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• 2003

This study was carried out to get a fundamental information fur improvement of reproductive performance in gilt. We investigated the effects of breeds on body weight, age, body length, wither's height, girth and backfat thickness, and the serum concentrations of estradiol-17$\beta$, cortisol and progesterone at first estrus and mating of gilts. A total of 47 gilts of Duroc, Landrace and Yorkshire, produced at Livestock Experiment Station, Chungnam Livestock Sanitation Research Institute from 2000 through 2002, were used for this experiment. Body weight, age and girth of Duroc at first estrus and mating were higher than those of Landrace and Yorkshire. There were no differences on body length among the three breeds at first estrus and mating. Wither's height of Duroc and Yorkshire at first estrus and mating was higher than that of Landrace. Backfat thickness of Yorkshire was thinnest among the three breeds at first estrus, but there were no differences on backfat thickness among the three breeds at first mating. Serum estradiol-17$\beta$ concentration of Landrace (45.0 pg/ml) at first estrus was higher than that of Yorkshire (27.4 pg/ml) and Duroc (21.8 pg/ml), but there were no differences on estradiol-17$\beta$ concentration (from 18.5 to 31.9 pg/ml) among the three breeds at first mating. Serum cortisol concentration of Duroc at first estrus and mating was higher than that of Landrace and Yorkshire. There were no differences on serum progesterone concentration among the three breeds at first estrus and mating of gilt.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.228-233
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• 2009

This study was conducted to examine the changes in the molecular structure and physiological activities of silk fibroin by gamma irradiation. The results of gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the molecular weight of fibroin was increased depending upon the irradiation dose. Secondary structure of fibroin determined by using circular dichroism revealed that the ratio of $\alpha$-helix was increased up to 10 kGy and then decreased depending upon the irradiation dose. Whereas, the ratio of $\beta$-sheet, $\beta$-turn, and random coil were decreased and then increased with an alteration in the $\alpha$-helix secondary conformation. The 2.2-diphenyl-1-picryl-hydrazil (DPPH) radical scavenging activity of fibroin was increased by gamma irradiation at 5 kGy, but was decreased above 10 kGy depending upon the irradiation dose. Also, the inhibition activities of tyrosinase and melanin synthesis of fibroin were increased by gamma irradiation. These results indicated that gamma irradiation could be used as an efficient method to make fibroin more suitable for the development of functional foods and cosmetics.

• Food Science of Animal Resources
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• v.23 no.4
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• pp.350-355
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• 2003

Raw skim milk and colloidal calcium phosphate-free skim milk were treated with microbial transglutaminase (TGase), ultracentrifuged at varying rates and were observed to contain textural properties using a scanning electron microscope (SEM). Skim milk showed irregular signs of conformation at lower centrifugal rate, and associated regular (10,000 ${\times}$g) and thin with broad holes (20,000 ${\times}$g). The associated texture became thick and irregular (40,000 ${\times}$g), and fine particles were regularly associated (100,000 ${\times}$g). When skim milk was incubated for 1 hr with TGase, casein micelles aggregated and broadened as centrifugation rate increased. When skim milk was incubated for 8 hrs with TGase, casein micelles associated to large widened aggregates, and were associated regularly which then became irregular (100,000 ${\times}$g). When colloidal calcium phosphate-free skim milk incubated for 1 hr with TGase showed no sediment, the milk incubated for 8 hrs with TGase associated together, yielding broadened and regular layers as the centrifugation rate increased. It is assumed that such phenomena could be caused by protein crosslinking reaction with TGase and conformational change of casein molecules, as well as dependencies on reaction time, temperature and ultracentrifugation rate.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.9-18
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• 1986

MNDO and STO-3G calculations were performed to determine relative stabilities of rotamers for ${\alpha}$-substituted acetones, $CH_2XCOCH_3$, X = F, Cl, OH, SH, and $NH_2$. It was found that rotamers corresponding to gauche forms are preferred for all the ${\alpha}$-substituents except for X = F and NH$_2$, for which the cis forms were the preferred ones. The stability of gauche form was dictated by the stabilizing two-orbital-two-electron interaction ${\sigma}_{cx}$-${\pi}_{co}^*$, operating uniquely in the gauche form due to the substantial vicinal overlap and energy gap narrowing between ${\sigma}_{cx}$ and ${\pi}_{co}^*$ orbitals. The energy gap narrowing was caused by the lowering of ${\pi}_{co}^*$ level due to the hyperconjugative ${\sigma}_{cx}^*$-${\pi}_{co}^*$ interactions; the red shift in the n-${\pi}^*$ transition was another effect of the relatively large ${\sigma}_{cx}^*$-${\pi}_{co}^*$ splitting. Various ${\sigma}-{\pi}$ interactions in the gauche form were found to be stronger in the third-row hetero atom system, X = Cl and SH. Interactions between nonbonding orbital on N, $n_N$ and vicinal C-C ${\sigma}$ bond were shown to be stronger in the trans than in the cis orientation.