• Korean Journal of Poultry Science
• /
• v.37 no.1
• /
• pp.69-80
• /
• 2010

Hypocholesterolemic effect of soy protein was examined in comparison with casein and three other dietary protein sources in chicks. In two feeding trials, 40 (Expt.1) or 50 (Expt. 2), three-day-old, male chicks were forced-fed each of five semi-purified-type diets containing isolated soy protein (ISP, cp 82%), casein (cp 92%), rice protein (RP, cp 70%), corn gluten meal (CGM, cp 65%) or fish meal (FM, cp 70%) for two weeks. The diets for Expt. 2 were supplemented with 0.3% cholesterol by replacing glucose. Each protein source was the only source of protein of each diet. Essential amino acids were added to the diets to satisfy their requirements according to NRC. The diets were forced-fed to equalize the intake of all nutrients except the amino acids which were inherently variable in the diets. Chicks fed casein showed lower body weight gain than those fed the other proteins in both experiments. Birds fed ISP and FM gained better body weight than the others. Chicks fed casein showed significantly higher levels of plasma total cholesterol, non-HDL cholesterol and triacylglycerol (TG) than those fed ISP and the other protein sources. Meanwhile, the chicks fed ISP, RP, CGM and FM showed comparable levels of plasma total cholesterol, non-HDL cholesterol and TG. In Expt. 2, the birds fed casein and FM showed markedly elevated plasma total cholesterol and non-HDL cholesterol levels. Liver weight and levels of total lipids and cholesterol of chicks fed casein appeared significantly higher than those of the other protein diets, whereas those of the chicks fed ISP, RP, CGM and FM appeared comparable except cholesterol in FM group. In conclusion, only the chicks fed casein diets in both experiments always showed significantly higher levels of plasma cholesterol and TG compared to those fed ISP and the other protein sources. These results support the views that casein, which has unique lysine-arginine ratio, is inherently hyper-cholesterolemic, and ISP is hypocholesterolemic only when compared to casein.

• The Korean Journal of Ecology
• /
• v.16 no.4
• /
• pp.515-526
• /
• 1993

In order to study the ecotypic variation of Rohinia pseudo-acacia L. distributed in southern area of Korean peninsula, 15 local populations(Daejin, Sokcho, Kangneung, Mt. Surak, Hongcheon, Kwangneung, Namhansanseong, Chungju, Yesan, Andong, Jeonju, Dalseong, Changweon, Mokpo and Wando), located from $34^{\circ}18'N\;to\;38^{\circ}36'N$, were selected based on the latitudes and geographical distances. Seeds of these populations were collected and protein contents of seeds and their band patterns were investigated. The seed proteins of all populations were electrophoresed on SDS-polyacrylamide gel. Total number of protein bands were 35, whose molecular weights ranged from 17, 258 daltons to 142, 232 daltons. The number of bands of seed proteins was 23 in Dalseong and Hongcheon and was 32 in Daejin and Sokcho, showing an increasing tendency in the number of bands as the latitude goes high. The local populations were classified into 3 local types based on protein analysis: the middle north east coastal type(Daejin, Sokcho. Kangneung), the central type (Mt. Surak, Hongcheon, Kwangneung, Namhansanseong, Chungju) and the southern type(Yesan, Andong, Jeonju, Dalseong, Changweon, Mokpo, Wando). According to the results of cluster analysis by UPGMA based on the similarity index(c0efficient of Jaccard) of the patterns, 3 local types were subdivided further into 6 types: the middle north east coastal type(Sokcho, Kangneung), the north central type I (Mt. Surak, Hongcheon), the north central type II (Narnhansanseong, Chungju, Daejin), the north central type III (Kwangneung), the south central type (Yesan, Dalseong, Jeonju) and the southern type(Andong, Changweon, Mokpo, Dalseong, Wando). The No. 12 band of the separated seed proteins showed the highest colored density in the preparations from all the populations. The No. 11~13 and No. 23~28 bands also showed high densities. As a whole, southern type populations (Changweon, Mokpo, Wando) showed high protein contents and high colored density. Total protein contents of the seeds in each population were variable from 9. 68mg / g (Mt. Surak) to 17.30mg/g (Jeonju), showing an increasing trends toward low latitudes.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.9 no.3
• /
• pp.155-162
• /
• 1976

Forty one samples from thirty three species of algae (19 from 15 species of Rhodophyceae, 18 from 14 species of Phaeophyceae, 3 from 3 species of Chlorophyceae, and 1 of marine Phanerogams) collected from several locations on the east, west and south coast of Korea, were analyzed for their contents of crude protein, fat, cellulose, ash, nitrogen free extract, amino nitrogen, and total amino acids. For the examination of extractability of algal protein with water, 4 species of algae, Sargassum thunberggi, Grateloupia filicina, Phyllospadix japonica, and Sargassum confusum, were analyzed. And the effect of some precipitation treatments for isolation of algal protein was also tested. As a matter of fact, Rhodophyceae showed high content in crude protein and low in crude fat while the case was opposite for Phaeophyceae and Chlorophyceae. Refering to the content of crude protein and total amino acids, the recommendable algae for protein sources were Sargassum thunbergii, Acrosorium flabellata, Phacelocarpus japonicus, Laurencia okamurai, Laurencia intermedia, Grateloupia filicina, Chondrus ocellatus, Gloiopeltis furcata, Gigartina tenella, Dictyota dichotoma, and Scytosiphon lomentaria. Methanol treatment appeared most effective in precipitation isolation of protein from water extracts whereas pH control method did not so beneficial. The precipitation rate of protein was particularity higher in the extract of Sargassum confusum ana the lowest was makted from the extract of Sargassum thunbergii.

• Korean Journal of Food Science and Technology
• /
• v.17 no.5
• /
• pp.389-398
• /
• 1985

To shorten the processing of cheese slurry, four different slurries, ie, Control, Cheddar 1 and 2, and Italian-type that were made of Na-caseinates, cream, trace elements, lactic culture, and enzymes were fermented at $30^{\circ}C$ for 7days with daily stirring. PH, titratable acidity, soluble nitrogen, viable cell count, active SH groups, total volatile fatty acid, free fatty acid, electrophoretic patterns of degraded caseins, and viscosity were analyzed to investigate physicochemical properties of fermented slurries. Acid production was accelerated in the cheese slurries with protease than that without the enzyme and PH of the former was decreased after three days of fermentation to 4.90. The Change of titratable acidity agreed to PH patterns. Soluble nitrogen of the Control slurry was increased slowly for four days and then rapidly to 40% of total nitrogen while those containing protease to 70%. The protease of lactic cultures used (Streptococcus lactis and Streptococcus cremoris) broke down as-casein more rapidly than $\beta$-casein and most proteins were degraded to peptides and amino acids after three days of fermentation. Total volatile fatty acids were increased by added lipase and free fatty acids composition analyzed by GLC in cheddar slurry with 0.00001% lipase was similar to that of commercial cheddar cheese, while that in Italian-type slurry was a half of that in commercial Italian cheese. Active SH groups were increased in the cheese slurries with glutathione from fourth day of fermentation. The viscosity of slurries decreased very rapidly by addition of protease.

• Korean Journal of Microbiology
• /
• v.31 no.2
• /
• pp.166-174
• /
• 1993

Streptomyces coeUc%r (Muller) cells were treated with $100 \mu$M hydrogen peroxide for I hour and proteins synthesized during hydrogen peroxide stress were labeled with L-[$^{35}S$]-methionine. Total cellular proteins were extracted and analyzed by two-dimensional polyacrylamide gel electrophoresis. In exponential growth phase, synthesis of about 100 proteins was increased by hydrogen peroxide treatment. These proteins were named as Pin (£eroxide-inducib]e) proteins and classified into 4 subgroups according to their induction time after hydrogen peroxide treatment. About 60 of them were found to be induced within 20 minutes and maintained throughout I hour of treatment. In stationary growth phase. synthesis of 62 proteins was increased by hydrogen peroxide and 21 of them were the same Pins found in exponential growth phase. Proteins from the mutants which are resistant to hydrogen peroxide were obtained in exponential growth phase and compared with those from the wild type on two-dimensional gel. The three mutants, N7, N9. and N24, were found to have higher constitutive leve]s of ]5, 17, and 15 Pin proteins respectively, than the wild type. 9 of these Pin proteins (D74.7a, E76.0c, E23.3. F50.7, F47.2a. F25.5, G39.6b, G24.0, H39.6a) increased in two of the three mutants and 3 proteins (F39.7, H6I.7. 120.8) increased in all of the three mutants. These proteins might play important roles in the response of S. coelic%r to hydrogen peroxide.

• Korean Journal of Microbiology
• /
• v.35 no.4
• /
• pp.270-276
• /
• 1999

Production of stress shock proteins in Burkholderia cepacia YK-2 in response to the phenoxyherbicide 2,4-dichlorophenoxyacetic acid(2,4-D) as an environmental contaminant was investrigated. The stress schock proteins were synthesized at different 2,4-D concentrations in exponentially growing cultures of B. capacia YK-2. This response involved the production of 43kDa and 41kDa GroEL proteins. The proteins were characterized by SDS-PAGE and Western blot using the anti-DnaK nad anti-GroEL monoclonal antibodies. Total stress shock proteins were analyzed by 2-D PAGE. Survival of B. cepacia YK-2 with time in the presence of different concentrations of 2,4-D was monitored, and viable counts paralleled the production of the stress shock proteins in this bacterium.

• Food Science and Preservation
• /
• v.15 no.6
• /
• pp.903-908
• /
• 2008

This study investigated protein changes in soymilk and whole soymilk due to enzymatic hydrolysis. The total free amino acid contents of low molecular weight soymilk (LSM) and low molecular weight whole soymilk (LWSM) were higher than soymilk (SM) and whole soymilk (WSM). The essential amino acid content was similar in SM and LSM, but was higher in LWSM than WSM. In SDS-PAGE performed to tendency of becoming low molecules, the soy protein molecular weights were 3372 kDa for SM and WSM, but 17 kDa or less for LSM and LWSM. Also, high molecular weight protein spots were evident in 2-D electrophoresis of SM and LSM, but only low molecular weight protein spots of various sizes were evident in WSM and LWSM. This suggests that the high molecular weight protein in SM and WSM is changed to low molecular weight protein by enzymatic hydrolysis. Further investigations of the separation and qualities of these proteins are required.

• Analytical Science and Technology
• /
• v.8 no.2
• /
• pp.181-186
• /
• 1995

The contents of sucrose and reducing sugars of cotyledons and hypocotyls of Ricinus communis L were increased slightly during cold treatment at $4^{\circ}C$. The concentration of total amino acids was increased continuosly during cold treatment. But the contents of hydrophilic amino acids, Asp/Asn, Glu/Gln, Thr, Ser, Ala and cationic amino acids, Arg and Lys were varied dramatically with the cold treated time. The cold treatment induced 24, 52, 54, 55, 56 and 73.5kD of proteins in cotyledons and 55, 56 and 73.5kD of proteins in hypocotyls. 24, 42, 49 and 52kD of proteins in cotyledons and hypocotyls were boiling stable. They were not denatrated by boiling at $100^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.19 no.2
• /
• pp.146-150
• /
• 1987

The effects of pH and added salts on the partition coefficients of proteins in a polyethylene glycol)-dextran aqueous two-phase system were investigated. The partition coefficients attained the lowest value at the isoelectric point of proteins in an equal volume aqueous two-phase system containing 5% PEG and 9.5% dextran in 5 mM phosphate buffer solution. The coefficients increased dramatically at pH 11; BSA which had highest effective hydrophobicity marked 50-fold increase, while ${\beta}-lactoglobulin$ and ovalbumin which had low hydrophobicity 10-fold increase, respectively. The effect of added salts varied with the pH. The partition coefficient increased by the addition of salt at pH 3.0 but decreased drastically at pH 7.0. The partition coefficient increased in the order of added Li < Na < K at pH 3.0 and decreased in the order of added Li < Na < K at pH 11.0.

• The Korean Journal of Mycology
• /
• v.16 no.3
• /
• pp.121-127
• /
• 1988

For selective purification of protein in Pleurotus cornucopiae (Per.) Rolland, affinity chromatography was performed by benzoyl-AH-Sepharose 4B gel synthesized using AH-Sepharose 4B with starting materials. Ligand capacity of benzoyl group was 9.3 micromole per milliliter of gel. Total apparent molecular weight of affinity protein was 255KD, which were protein complex of 29.5, 31.5 34.0, 71.0 and 89.0KD, respectively. The contents of nonpolar, polar, positively charged, and negatively charged amino acid were 45.68%, 26.93%, 11.81% and 15.58%, respectively. The nonpolar protein was selectively purified by hydrophobic ligand of benzoyl group of gel.