• Journal of Aquaculture
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• v.21 no.4
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• pp.285-293
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• 2008

Vitellogenin (Vg) is the precursor of vitellin (Vn), the major yolk protein of teleost fishes. In this study, Vg and Vn proteins of the Korean bullhead Pseudobagrus fulvidraco were isolated using gel-filtration chromatography (Sephadex-G 200 column) and anion-exchange chromatography (Mono Q HR 5/5 column), respectively. Purified Vn with an estimated molecular mass of 360 kDa by gel filtration chromatography was obtained from ovarian egg, and it was composited to one major subunit with an estimated molecular mass of 107 kDa by SDS-PAGE. In the result of western blotting, one major band was detected using antiserum against Vn (anti-Vn). These results suggested that Vn was composed of three subunits having the same molecular weight in Pseudobagrus fulvidraco. Vg was induced by estradiol-$17{\beta}$ ($E_2$) and purified from $E_2$ treated male serum. The molecular weight of whole Vg was estimated to be 450 kDa by gel filtration chromatography, and it is composed of three subunits with estimated molecular masses of 110 kDa, 125 kDa and 147 kDa as determined by SDS-PAGE. In the Ouchterlony's immunodiffusion test using anti-Vn and antiserum against female and male serum, purified Vg was detected in matured female and Ez treated male serum but not in untreated male. These results can be used in detecting estrogenic contamination of the aquatic environment.

• BMB Reports
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• v.40 no.2
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• pp.212-217
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• 2007

The chicken oviduct is a dynamic organ that produces secretory proteins such as ovalbumin during the laying period. In this study, we identified oviduct-specific proteins in hens during the egg-laying period by proteomic analysis. Proteins extracted from the magnum of hens of different ages (5, 35, and 65 weeks) were analyzed by two-dimensional gel electrophoresis to compare the intensity of proteins among samples. Approximately 300 spots were detected on each gel. Based on the comparison of image gels, we found that the intensity of eight spots in 35-week magnums was increased at least by 2-fold compared with the others. Five of the eight spots were identified as calumenin, acidic ribosomal phosphoproteins (ARP), prohibitin, heart fatty acid-binding protein, and anterior gradient-2 (AGR-2). In particular, ARP and AGR-2 were highly expressed in 35- week magnums compared with 5- and 65-week magnums. In addition, the level of these proteins was consistent with their RNA levels. Expression of AGR-2 mRNA was detected in the mature magnum, whereas no signal was observed in premature tissue. Among various tissues, expression of AGR-2 mRNA was highest in the magnum, high in the isthmus, and five fold lower in muscle. It was undetectable in the liver and in other tissues (heart and kidney). However, the mRNA levels of other proteins were ubiquitous among tissues. In transcriptional activity of AGR-2, a 3.0 kb fragment of promoter region containing potential estrogen receptor binding sites had enhanced its activity strongly. In conclusion, these results suggest that AGR-2 has functional regulatory roles in the chicken oviduct during the egglaying period.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.117-121
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• 2004

The patterns of diapause-associated proteins of silkworm eggs were analyzed by two-dimensional (2-D) gel electrophoresis. Among the hundreds of spots on the 2-D gels, at least two proteins were considered to be associated with diapause. A protein, spot 4, with an approximate molecular weight of 38 kDa and pI 6.1 was observed in the HCI-treated, cold-treated, and diapause eggs, respectively. Spot 4 was undetectable in unfertilized eggs and non-diapause eggs at two days after oviposition, suggesting that this protein may be associated with the entrance to diapause. A protein, spot 11, with an approximate molecular weight of 21 kDa and pI of 61 was detected in the unfertilized, HCl-treated, and cold-treated eggs, respectively, after oviposition by normal moths. In diapausing eggs, a protein corresponding to spot 11 was observed in 3-, 5-, and 30-day-old eggs, while the protein was not detected one-day-old eggs. The protein corresponding to spot 11 was not detected in unfertilized and non-diapause eggs obtained from subesophabeal ganglion (SG)-extirpated moths either. Spot 11 was also considered to be a diapause specific protein, which occurred at only early embryonic stage under the control of diapause-downregulated gene.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.37-48
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• 2008

The diapause and non diapause associated proteins of multivoltine silkworm eggs were analysed by two dimensional (2D) gel electrophoresis. The study was made at 0 hr, 24 hrs and 48 hrs after oviposition. A total of four protein spots in diapause eggs at 24 hrs of oviposition and two protein spots in non diapause eggs at 0 hrs of oviposition were observed. All the six protein spots were considered to have association with diapause and non diapause characters. The molecular weight (MW) and isoelectric point (PI) of these 6 protein spots were calculated. The protein spots 1 and 2 observed in 0 hr of non diapause eggs were found to have the MW of 67 and 75 KDa and PI of 8.6 and 8.4 respectively. Similarly the four protein spots observed in diapause egg at 24 hrs of oviposition exhibited MW viz., 15, 17,20 and 25 KDa and PI of 5.3, 5.8, 6.5 and 6.0 respectively. All these 6 identified protein spots were subjected to in-gel digestion and resulted tryptic peptides were analyzed by Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI TOF-MS). Databases searched based on experimentally determined molecular weights of peptides for the determination of the identities of proteins. The identified proteins indicated homology of 34% to 95%. The results indicate that the proteins may playa role in development of diapause and non diapause eggs.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.73-86
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• 1988

The sensitivity and specificity of crude and affinity-purified antigens of Clcnorchis sinensis obtained from the infected rabbits were studied. Stage-specific antigenic proteins from the eggs, metacercariae and adult worms were characterized by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent astray (ELISA). The results were as follows: 1. The antibody.binding antigen (ABA) purified from whole worm crude antigen (IVWA) by CNBr-activated Sepharose 4B affinity chromatography made :l specific bands against rabbit antisera on Ouchterlony gel diffusion plate, while WWA made 7 bands. Major WWA protein bands by SDS-PAGE were found at 16, 300~18, 500 and 28, 000~29, 000 daltons, while major ABA protein bands were at 18, 000~21, 000 and 29, 000~31, 000 daltons. The reactivity of ABA with rabbit anti-sera in ELISA was remarkably less sensitive than that of WWA. 2. Molecular weights of egg antigen (EGA), metacercarial antigen (MEA) and adult worm antigen (WWA) of C. sinensis ranged from 15, 000-200, 000 daltons, 15, 000-100, 000 daltons and 11, 000~80, 000 daltons, respectively. Major WWA proteins consisted mainly of polypeptide bands of low molecular weight, less than 31, 000 daltons, while those of EGA and MEA consisted of higher molecular T.eights than 30, 000 daltons. 3. The ELISA reactivities of WWA to rabbit anti.sera were remarkably greater than those of MEA. EGA showed negative reaction throughout the experiments. WWA showed higher optical density (O.D.) than 1.0, when reacted with rabbit anti-sera obtained at 4~6 weeks after the infection. In the rabbit anti-sera later than 12 weeks after the infection, the O.D. reacting witll WWA showed a plateau without variation. MEA shoT.ed relatively low O.D. values (<0.6), when reacted with anti-sera from lightly in(ected groups throughout the experiments, althougll there were some wealth positive cases (O.D.>0.6) ill heavily infected groups. MEA reacted with rabbit anti-sera showed negative results on Ouchterlony gel diffusion plates. Summarizing the above results, it is suggested that the whole worm antigen prepared from the adult worms of C. sinensis is most highly antigenic. However, this antigen might reveal cross reactions with other trematodes such as Paragonimus westermani, therefore, purification of antigenic proteins from the crude antigen is essential 18 increase the sensitivity and specificity for the immuncdiagnosis of clonorchiasis.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.337-344
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• 1996

Gel-type yogurt was prepared from egg white powder (EWP), casein and glucose. The effects of EWP on acid production and growth of Lactobacillus were studied. The effect of EWP on sensory properties and volatile aroma compounds were also studied. Acid production by Lactobacillus in EWP (1-3%, W/V) was significantly lower than that by Lactobacillus in milk (control). However, the increase of EWP content from 1 to 3% increased acid production significantly, Number of viable cells of L. acidophilus at 24 hrs in milk and EWP containing samples (1-3%) was $3.1{\times}10^4/ml\;and\8.3{\times}10^7-3.6{\times}10^2/ml.$ respectively Sample containing lower amount of EWP generally showed lower number of viable cells. Sensory property of EWP samples (1-3%) was showed lower than that of milk yogurt (reference). However, sensory property of samples containing EWP 2% or 3% was significantly better than that of sample containing EWP 1%. Though the composition of volatile aroma compounds was slightly different from sample to sample, gas chromatographic analysis detected acetone, ethanol, diacetyl and acetoin in samples fermented by L. acidophilus.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.546-554
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• 1997

Gel-type yogurt was prepared from egg white powder (3%, w/v), glucose (2%, w/v) and four kinds of milk products (4%, w/v). The effects of milk product on acid production and growth of Lactobacillus were studied. The effects of milk product on sensory property and volatile aroma compounds were also studied. Acid production by L. acidophilus at 24 hr in samples containing milk product was significantly lower than that by L. acidophilus in milk (p<0.05). The sample containing casein produced less acid than the other samples. Number of viable cells of L. acidophilus at 24 hr in milk and samples containing milk product was $2.0{\times}10^{9}/mL$ and $5.0{\times}10^{8}{\sim}8.0{\times}10^{8}/mL$, respectively. Sensory property of the samples containing milk product was lower than that of milk yogurt (reference). However, sensory property of the sample containing casein was not significantly different from that of milk yogurt (p<0.05). The sample containing whey powder showed lower sensory score than other samples. Though the composition of volatile aroma compounds was slightly different from sample to sample, gas chromatographic analysis detected acetone, ethanol, diacetyl and acetoin in samples fermented by L. acidophilus.

• The Korean Journal of Zoology
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• v.23 no.3
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• pp.125-136
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• 1980

The purpose of the present study is to investigate the electrophoretic patterns of ADH isozymes and activity at various developmental stages of Oregon-R and Kwangju strains of D. melanogaster. The ADH isozymes were seperated by agarose gel plate eletrophoresis and they were stained for ADH activity study. The optical density was measured by using densitometer and the total activity was determined by measuring the enzyme solution's absorbance of 340 nm by spectrophotometer. The results are as follows: 1. At egg stages of Oregon-R and Kwangju strains ADH 2, ADH 3, ADH 4 were observed in te zymograms, but all of ADH 1, ADH 2, ADH 3, ADH 4 and ADH 5 were detected in larval, pupal and imaginal stages. 2. The amount of ADH 1+ADH 2 (anion) was 20-40% and that of ADH 3+ADH 4+ADH 5 (cation) was 60-805. In the developmental stages other, than egg stages, ADH 3 of both strains showed the largest amount among all ADH isozymes, and especially ADH 4 of Kwangju strain showed less amount than that of Oregon-R strain. 3. The total activity of the ADH at the egg stage was found to be the lowest, at larval stage became to be higher and to be lower at pupal stage and then became to be the highest at the imaginal stage. It is noticeable that the activity of the ADH in Kwangju strain was higher than that in Oregon-R strain.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.131-135
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• 2000

The vitellin of the fireflies, Luciola unmunsana and L. lateralis was characterized. The vitellin of L. unmunfon is composed of two subunits, designated Vnl (195 kDa) and Vn2 (185 kDa) in SDS-polyacryamide gel electrophoresis. These two subunits of vitellin of L. unmunsana gradually decreased during embryogenesis. As expected, these protein bands were presented in female adult hemolymph and egg extracts, but not in male. The vitellin of L. lateralis is also composed of two subunits, designated Vnl (195 kDa) and Vn2 (180 kDa) in SDS-PAGEi and these two protein bands gradually decreased during embryogenesis. Western blot analysis using each of polyclonal antiserum against vitellins of L. unmunsana and L. lateralis showed that two antisera strongly crossereacted with vitellin subunits of L. unmunsana and L. lateralis, suggesting that vitellins of L. unmunsana and L. lateralis have similarity with each other.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.236-239
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• 2004

Microbial contamination of ready-to-eat ingredients for Kimbab manufacturing and the effect of irradiation to reduce the microbial contamination of the products were investigated. Among 9 food items tested, there were no viable cells in the ham, seasoned and cooked beef, imitation crab leg, fried egg, and seasoned burdoc. Cucumber, surimi gel, and seasoned and blanched spinach were counted at 5.07$\pm$0.97, 3.50$\pm$0.14, and 5.41$\pm$0.51 log CFU/g, respectively. Irradiation at 1 kGy reduced the number of microorganism in these ready-to-eat foods to an undetectable level. However, the dried laver showed an 8.83$\pm$0.10 log CFU/g and an irradiation at 3 kGy reduced the level to only 7.14$\pm$0.23. Sensory evaluation of the irradiated Kimbab prepared from these food materials indicated that the measure of the control of the sensorial quality should be provided before applying an irradiation to the prepared Kimbab.