• Journal of Nutrition and Health
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• 제22권6호
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• pp.497-506
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• 1989

To investigate the effect of levels of dietary protein and age on bone metabolism 40% and 5% casein were fed to the rats of 2 & 13 months of age for 12 weeks. High protein groups showed higher bone weight and Ca content than low protein groups and urinary Ca loss was increased in high protein groups but the difference disappeared gradually. A significant increase in urinary hydroxyproline excretion was noted in high protein groups of both age. Another short term study was undertaken to study if the above effect was related with renal function or PTH. Extremely high and low protein diets(60%, 6%) were fed to the rats of different ages(6wks, 6mos.) for 2 weeks, Urinary Ca excretion was significantly increased in high protein groups of young and aged rats and GFR was increased as well. There was no difference in serum iPTH levels between low and high protein groups, but it was elevated in aged rats. Alkaline phosphatase activity was higher in young rats, reflecting faster bone formation. The observed hypercalciuria in high protein groups, especially in aged rats, seems to be related to higher GFR, and PTH dose not appear to be a major mediator.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.502-506
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• 1996

Protein X is one of the subunits of pyruvate dehydrogenase complex. The biological role of this protein has not been fully elucidated, mainly because of the difficulty in its dissociation from the tightly bound dihydrolipoamide acetyltransferase-protein X subcomplex. We have found that the detachment of protein X from acetyltransferase subunit can be easily accomplished by the cycles of freezing and thawing proces. Several lines of evidence including sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequence analysis and acetylation with $[2^{14}C]$ pyruvate confirmed that the purified protein is protein X. The purified intact form of protein X was acetylated by $[2^{14}C]$ pyruvate in the presence of py-ruvate dehydrogenase subunit.The acetylation efficiency of this protein was lower than that of acetyltransferase and was not affected by the presence of acetyltransferase.

• 약학회지
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• 제42권1호
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• pp.46-52
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• 1998

Retroviral integrase is required for integration of viral DNA into the host cell chromosome. Human immunodeficiency virus type-1 integrase was partially purified as a part of a fusion protein linked to a maltose-binding protein and characterized in terms of an endonucleolytic activity. The concentration of the fusion protein purified through an amylose column was about 12mg/ml. Indicating that the solubility of the fusion protein is highly increased by the presence of a maltose-binding protein, considering that the integrase protein alone is poorly solubilized. The endonucleolytic activity of the fusion protein was detected at 0.1 to 1.OmM $Mn^{++}$ ion, but not at any concentrations tested of $Mn^{++}$ ion.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.70-76
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• 2001

This experiment was conducted to investigate the effects of crystalline isoleucine supplementation of a low protein, corn-soybean meal diet on the performance and immune function of weanling pigs. Forty-five crossbred ($Duroc{\times}Landrace{\times}Large\;White$) piglets, weighing an average of $11.00{\pm}0.07kg$, were assigned to either a control diet containing 20% crude protein (0.64% isoleucine), a 16% crude protein diet without isoleucine supplementation (0.41% isoleucine) or a 16% crude protein diet supplemented with isoleucine (0.64% isoleucine). Reducing the crude protein content of the diet from 20 to 16% significantly (p<0.05) reduced both average daily gain and feed intake. Feed conversion also tended (p=0.07) to be poorer for a low protein diet without isoleucine supplementation. Isoleucine supplementation of the 16% crude protein diet increased both gain and feed intake to a level similar to that obtained by pigs fed the 20% crude protein diet (p>0.05). Blood urea nitrogen, serum total protein and serum globulin were significantly (p<0.05) higher for pigs fed the unsupplemented 16% crude protein diet than for pigs fed the isoleucine-supplemented diet or the control. Egg albumin antibody titre decreased significantly (p<0.05) in pigs fed the diet with isoleucine supplementation, whereas the antibody titre of pigs fed the low protein and low isoleucine diet was similar to that of pigs fed the diet containing 20% crude protein and 0.64% isoleucine. It was suggested that crystalline isoleucine supplementation of a low protein and low isoleucine diet improved pig performance but suppressed humoral immune function.

• Asian-Australasian Journal of Animal Sciences
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• 제18권9호
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• pp.1285-1293
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• 2005

The present study was conducted to evaluate and compare the effects of various animal and plant protein sources on piglet' performance, digestibility of amino acids and gut morphology in weaned pigs until 28 days after weaning. The plant protein sources used were soybean meal (SBM), fermented soy protein (FSP), rice protein concentrate (RPC); and animal protein sources tested were, whey protein concentrate (WPC) and fishmeal (FM). Iso-proteinous (21%) diets were formulated and lysine (1.55%) content was similar in all the diets. The level of each protein source added was 6% by replacing SBM to the same extent from the control diet containing 15% SBM. The ADG was higher (p<0.05) in the groups fed animal proteins as compared with plant proteins at all the levels of measurement, except during 15-28 days. The highest ADG was noted in WPC and FM fed diets and lowest in SBM fed diet. The feed intake was higher in animal protein fed groups than plant proteins at all phases, but the feed:gain ratio was not affected by protein sources except during overall (0 to 14 day) measurement which was improved (p<0.05) in animal protein fed diets compared to plant protein sources. The digestibilities of gross energy, dry matter and crude protein were higher in animal protein fed groups than for plant protein fed sources. The apparent ileal digestibilities of essential amino acids like Leu, Thr, and Met were significantly (p<0.05) higher in animal proteins fed animals as compared with plant protein fed animals. But the apparent fecal digestibilities of essential amino acids like Arg and Ile were significantly higher (p<0.05) in plant protein diets than animal protein sources. The villous structure studied by scanning electron microscope were prominent, straight finger-like, although shortened and densely located in FM fed group as compared with others. The lactic acid bacteria and C. perfringens counts were higher in caecal contents of pigs fed plant proteins than the animal proteins. Overall, it could be concluded that animal protein sources in the present study showed better effects on growth performance, nutrient digestibility and gut morphology than plant protein sources.

• 한국양식학회지
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• 제21권4호
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• pp.239-243
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• 2008

A $3{\times}2$ factorial experiment was conducted to investigate the proper dietary protein and lipid levels for the growth of sub-adult flounder Paralichthys olivaceus reared during the summer season. Six experimental diets were formulated to contain three levels of protein (45%, 50% and 55%) and two levels of lipid (9% and 14%). Duplicate groups of fish (initial body weight of 298 g) were hand-fed to apparent satiation during the summer season ($21.8{\pm}1.7^{\circ}C$) for 60 days. Survival of each group was over 83% and there was not significant difference among all groups. Weight gain of fish fed the 45% protein diet with 14% lipid was not significantly different from that of fish fed the 50% and 55% protein diets with 9% and 14% lipids, but weight gain of fish fed the 45% protein diet with 9% lipid was significantly lower than that of fish fed the 55% protein diets with 14% lipid. Feed efficiency tended to increase with increasing dietary lipid level at each protein levels, although no significant differences were observed at 50% and 55% protein levels. Protein efficiency ratio, daily feed intake, condition factor and hepatosomatic index were not significantly affected by dietary protein and lipid levels. Crude lipid content of the liver tended to increase with increasing dietary lipid level at the same protein levels, but the opposite appearance was found for moisture content. The contents of moisture, crude protein and crude lipid of the dorsal muscle were not significantly affected by dietary protein and lipid levels. Based on data obtained form this study, inclusion of dietary protein at level of 45% appears sufficient to support optimal growth, and an increase of dietary lipid level from 9% to 14% has beneficial effects on feed utilization of sub-adult flounder during the summer season.

• Journal of Nutrition and Health
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• 제29권10호
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• pp.1059-1071
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• 1996

This study was performed to investigate the effect of dietary protein level on renal senescence. Male rats of 337.8$\pm$5.7g body weight were underlateral nephrectomy or shamoperation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein)diets and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. There was a hypertophy of the remnant kidney of uninephrectomized rats of 40% or 15% protein group, coming up to the comparable weights of both kidneys of sham-operated rats. However, the hypertrophic effect was not seen in uninephrectomized rats of 8% protein group. Serum albumin was lower in uninephrectomized rats. With increasing dietary protein level blood urea nitrogen was increased, whereas, urinary urea nitrogen excretion was decreased. Urinary solute excretion was higher in uninephrectomized group than in sham-operated group. However, effect of dietary protein level on urinary solute excretion varied dpending on th solutes tested. GFR and urinary protein excretion, throughout experiment, increased with feeding period and with dietary protein level. Proteinuria was most severe in uninephrectomized rats fed 40% casein diet. Maximum urine concentration ability measured after dehydration was not different among the experimental groups. Light microscopic examination showed focal segmental glomerulosclerosis and mild increas of glomerular mesangial matrix in uninephrectomized rats fed 40% and 15% protein diet, however, which was not observed in uninephrectomized rats fed 8% protein diet and in sham-operated rats fed 40% diet. Immunofluorescence studies revealed segmental deposits of albumin in the mesangium and capillary loops in high protein and uninephrectomized groups. Minimal granular deposition of IgG was noted in the mesangium of all experimental groups. In conclusion, high protein intake accelerated deterioration of renal function and it was correlated with morphological change. Low protein intake was effective in preventing these changes.

• 한국콘텐츠학회논문지
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• 제18권3호
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• pp.648-657
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• 2018

본 연구는 한국인에게 적합한 단백질 바를 개발하기 위하여 한국과 미국의 시판되고 있는 단백질 바의 라벨 분석을 하였다. 또한 조사한 단백질 바의 단백질 함량과 일일단백질섭취량, 단백질 권장섭취량(DRI), 그리고 단백질 에너지섭취분율(AMDR)과 비교 분석하였다. 단백질 바는 두 나라의 오프라인과 온라인 마켓을 통해 한국의 17개 제품과 미국의 113개 제품을 수집하였고, 영양소 함량과 원재료를 조사하였다. 그 결과, 미국의 단백질 바가 한국의 것에 비해 1회 제공량이 더 많기 때문에 전체적인 영양소의 함량도 높았는데, 특히 100g으로 환산하였을 때 단백질과 나트륨의 함량은 큰 차이로 높았다. 원재료를 통한 단백질 소재를 분석하였을 때, 한국은 분리대두단백(SPI)이, 미국은 분리유청단백(WPI)이 가장 많이 이용되었다. 이는 나라별 식품의 선호와 친숙함에 영향을 받은 것으로 보인다. 결론적으로, 두 나라의 식습관과 단백질 급원에 대한 섭취 및 선호가 다르기 때문에 한국인에게 적합한 단백질 바의 개발이 필요할 것으로 사료되며, 본 연구의 결과는 소비자들이 단백질 바를 선택하는 데 도움을 줄 것이다.

• 동아시아식생활학회지
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• 제7권1호
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• pp.13-20
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• 1997

This study was designed to determine the effects of protein sources on the curation of gastric ulceration, protein metabolism, and nitrogen balance in rats with gastric ulcer induce by restraint and water immersion stress. After the rats were fed 10% casein diet for 3 weeks, four groups of the rats were forced in 5$\times$5$\times$15cm plexiglass cage. The restraint and water immersion stress was carried at 20$\pm$2$^{\circ}C$ for 8-hour. The other one group(control group) was not exposed to stress. After stress 4 kinds of different diets containing 20% protein were given for 5 days. The protein sources were casein, whey protein, soy protein, gluten. The control group was fed to 10% casein diet. The results were as follows ; the weights of rats were not different among the diet groups During the experiment period follows ; the weights of rats were not different among the diet groups during the experiment period (for 5 days). The ulcer index of rats fed 10% gluten and soy protein diet was significantly higher than those of casein and whey protein diet groups(p<0.05). The level of serum albumin was not significantly different among diet groups. But hematocrit and the level of $\alpha$-amino-N, BU and UUN of plant protein diet groups were higher than animal diet groups, the urinary hydroxyproline of soy protein group was the highest and the whey protein was the lowest. The digestibility and BV of nitrogen of gluten diet group were significantly higher than those of casein and whey protein diet groups(p<0.05). The animal proteins had more curative effects of ulcer than plant animals. The results of this study provide useful information concerning diet therapy for the patients with gastrointestinal diseases and the field of enteral diet materials.

• Applied Microscopy
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• 제29권4호
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• pp.499-509
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• 1999

완두 종자에 축적되는 저장물질은 주로 전분과 단백질로서 이러한 저장물질 때문에 고정이나 전자현미경 관찰시료를 제작하기가 쉽지 않다. 따라서 자엽을 얇게 절편을 만들고 효소를 사용하여 단일세포로 분리한 다음 고정하여 관찰하였다. 완두의 저장단백질이 축적되는 단백질 저장 액포는 종자발달의 이른 시기에 기존의 액포를 둘러싸고 발달하게 되므로서 액포는 수축되고 단백질 저장 액포는 점점 발달하여 그 가장자리에 단백질 덩어리가 축적되게 된다. 이와는 별도로 종자발달의 이른 시기에 조면소포체의 내강에 전자밀도가 높은 단백질이 축적되기 시작하여 늦은 시기에 이 소포체의 끝이 부풀어서 구형의 단백과립으로 발달하였다. 완두종자의 저장단백질은 주로 vicilin과 legumin으로서 단백과립에 대한 면역세포화학적 방법으로 확인한 결과 vicilin은 세포질에 발달된 작은 단백과립과 단백질 저장액포의 가장자리에 축적된 단백질 덩어리에 모두 반응하였으나 legumin은 세포질의 단백과립에만 반응하였다. 또한 소포체에 존재하는 단백질인 Bip은 단백질 저장액포에 축적된 단백질 덩어리의 안쪽 가장자리에만 반응하였다. 이는 단백질이 활발하게 축적되고있는 시기에 특징적으로 작용하는 Bip의 기능과 관련되는 것으로 사료된다.