• 한국식품과학회지
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• 제12권4호
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• pp.263-271
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• 1980

피마자박 단백질을 사료 또는 식품화 하기 위하여 탈지 피마자박으로부터 독성분이 완전하게 제거된 단백질을 만들었다. 이 피마자 단백질의 용해도는 ${\varepsilon}$-아미노기의 숙시닐화 및 아세틸화로 $pH\;7{\sim}8$에서 현저하게 증가하였다. 아미노산 분석결과, 황-함유 아미노산과 L-리신이 제한 아미노산이었고, 아실화 과정은 아미노산 함량에 약간의 손실을 주었다. 파파인을 이용한 1 단계법 plastein 반응으로 피마자 단백질 또는 아실화 피마자 단백질과 DL-메티오닌 에틸 에스테르로부터 L-메티오닌 강화 피마자 단백질을 합성하였고, 이 방법으로 L-메티오닌 도입율은 50%였다. 피마자 단백질 및 수식된 피마자 단백질의 펩신에 의한 소화율은 모두 92% 정도였으나, 트립신에 의한 소화율은 숙시닐화 및 아세틸화 단백질이 현저하게 떨어져서 각각 42% 및 26%였다. 피마자 단백질의 단백질 효율은 L-메티오닌 강화로 카제인의 단백질 효율의 90%까지 향상되었으나, 피마자 단백질을 숙시닐화 및 아세틸화 하면 단백질 효율은 감소되어, 각각 카제인의 55% 및 69%였다.

• 한국가금학회지
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• 제12권1호
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• pp.17-24
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• 1985

비단백태질소가 단백질의 생물적이용성에 미치는 영향을 조사하기 위하여 무단백 혹은 단백질사료에 0, 0.5, 1.0 및 1.5%의 요소가 각각 첨가되었다. 갓 부화한 단관백색 레그혼 숫병아리에 8주간 병아리용 시판사료를 급여하고 6일간을 무단백사료 다음 6일간 실험사료를 급여하였다. 무단백사료 급여시에는 요소첨가량이 증가함에 따라 사료섭취량이 감소하는 경향을 나타내었으나 체중감소량은 서로 비슷하였다. 단백질사료를 급여하였을 때는 증체량과 사료소비량은 요소첨가에 의한 영향이 없었으나 사료요구율은 요소첨가량이 증가함에 따라 높아지는 경향이 있었다. 단백질이용효율(PER)과 정미단백가(NPR)은 요소첨가량이 증가함에 따라 무단백사료를 급여한 것에서 증가하나 단백질사료를 급여한 것에서 감소하는 경향이 있었다. 요산태질소의 배설은 요소첨가량이 증가함에 따라 무단백사료를 급여하면 특별한 경향은 없었으나 단백질사료를 급여한 것에서는 증가하는 경향이 있었다. 크레아틴태질소의 배설은 요소첨가의 경향이 뚜렷하지 않았다. 암모니아태질소의 배설은 요소첨가량이 증가함에 따라 무단백사료를 급여했을 때는 증가하는 경향이, 단백질사료를 급여했을대는 특별한 경향이 없었다. 한편 요소태질소의 배설은 무단밸 및 단백질사료를 급여한 것에서 요소첨가량이 증가할수록 증가하였다. 무단백사료를 급여한 병아리의 질소밸런스는 부의 값이었으나 요소첨가량이 증가함에 따라 증가하였다. 단백질사료를 급여한 것의 질소밸런스와 요중질소배설량은 요소첨가량이 증가함에 따라 증가하였으나 분중 배설량질소량은 특별한 경향을 나타내지 않았다. 무단백사료에 첨가된 요소질소의 소화율은 요소첨가률이 높아짐에 따라 낮아지는 경향이 있었으나 생물가(BV)와 정미단백질이용율(NPC)은 1.5%의 요소가 첨가되면 높아지는 경향이 있었다. 단백질사료를 급여한 병아리에서는 단백질의 소화율, BV 및 VPU가 0.5%의 요소가 첨가되었을 때 높아지는 경향이 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제1권1호
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• pp.7-12
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• 1988

Twenty cows, by order of calving, were used in a completely randomized $2{\times}2$ factorial experiment. Variables were tow protein levels (14 and 18% crude protein) and concentration of fat (2 and 6% ether extract) in diets. Fat addition, via unprocessed whole sunflower seed, insured forage utilization in diets to meet energy requirement of cows. A total of 36 wks of lactation was subdivided into three 12-wk stages of lactation. Net energy lactation was set at 1.72, 1.57 and 1.42 Mcal/kg for each stage. Higher protein diets improved the efficiency of energy (FCM/net energy intake) which was particularly noted for diets containing high fat (85.7%). However, diets with low protein-high fat resulted in the lowest efficiency (67.7%). No difference in milk yield and butterfat was due to different levels and combinations of protein and lipid in diets. High protein diets depressed blood cholesterol and glucose compared to low-protein counterparts. Relative decline in milk production was slower for lower fat diets than for higher fat groups, especially mid to later stage of lactation. Results of this experiment tend to support our thesis on the synergistic effect of dietary protein and energy (lipid) upon efficiency of lactation.

• 생명과학회지
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• 제8권1호
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• pp.109-117
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• 1998

The synthesis and methylation in vivo of myleline basic protein(MBP) during the mouse brain devlopment was found to be the highest in youngest brain and declined progressively in mature brains. The relative rate of protein synthesis and methylation was a maximal ration in the youngest brain, This high ratio was wdll correlated with the higher protein methylase I (PM I) activity in younger brains. The jimpy mouse is the most severely affected dysmyelinating mutant and is characterized by failure to incorporate MBP into myelin. sheath. The MBP-specific PM I activity in 15-, 18-, and 21-days old hemizygous jimpy mice(jp/y)brains decreased by 20, 50 and 75%, respectively. Myelin fraction with different degrees of compaction were isolated from bovine brain, the most compact myelin fraction exhibited higher methylaccepting activity than the less compact dense fractions.

• Applied Biological Chemistry
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• 제36권3호
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• pp.172-177
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• 1993

참깨박에 함유되어 있는 불용성 형태의 단백질을 Bacillus sp. CW-1121이 생성하는 효소를 이용하여 가용성 형태의 단백질로 용출시키기 위하여 효소를 작용시켰다. 효소 처리 참깨박 단백질의 기포 형성력은 염용성 단백질이 수용성 단백질에 비해 현저히 낮았다. 기포 안정성은 염용성 단백질이 10분 이내 크게 감소된 반면 수용성 단백질의 기포 안정성은 30분 까지 완만하게 감소하였다. 유화력은 각 단백질의 등전점 부근에서 가장 낮았으며, 염용성 단백질이 수용성 단백질에 비해 낮았다 유화 안정성은 유화력과 비슷한 크기로 나타나 $80^{\circ}C$에서의 30분 가열에서도 이들 단백질이 열에 안정함을 보였다. 유지 및 수분 흡착력은 염용성 단백질이 수용성 단백질 보다 높은 값을 나타내었다.

• Fisheries and Aquatic Sciences
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• 제23권1호
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• pp.1.1-1.14
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• 2020

Background: Dietary protein requirements are dependent on a variety of factors and water temperature is one of the most important abiotic factors affecting protein requirement of fish. This study was, therefore, conducted to investigate effects of water temperature on dietary protein requirement of fry Heteropneustes fossilis which has high demand in most of the Asian markets. Methods: Quadruplicate groups of 30 fish per treatment (2.97 ± 0.65 cm; 5.11 ± 0.34 g) were fed seven isoenergetic diets (17.9 kJ g^-1 gross energy; 14.99 kJ g^-1 digestible energy) containing dietary protein levels ranging from 28 to 52% at two water temperatures (18 and 26 ℃). Experimental diets were fed to apparent satiation as semi-moist cakes thrice daily at 17:00, 12:00, and 17:30 h for 12 weeks. For precise information, various growth parameters, protein deposition, hematological parameters, metabolic enzymes, and stress response were analyzed, and effects of water temperature on dietary protein requirement was recommended on the basis of response from above parameters. Results: Groups held at 26 ℃ attained best growth, feed conversion, and protein deposition at 44% dietary protein indicating that temperature affected dietary protein requirement for optimum growth of H. fossilis fry and protein requirement seems to be satisfied with 44% dietary protein. Interestingly, interactive effects of both dietary protein levels and temperature were not found (P > 0.05). Fish reared at 18 ℃ had comparatively higher values for aspartate and alanine transferases than those reared at 26 ℃ water temperature which exhibited normal physiological value for these enzymes indicating that body metabolism was normal at this temperature. Hematological parameters also followed same pattern. Furthermore, fish reared at 26 ℃ water temperature exhibited more resistant to thermal stress (P < 0.05). The 95% maximum plateau of protein deposition data using second-degree polynomial regression analyses exhibited dietary protein requirement of fry H. fossilis between 40.8 and 41.8% of diet at 26 ℃ water temperature. The recommended range of dietary protein level and protein/digestible energy ratio for fry H. fossilis is 40.8-41.8% and 27.21-27.88 mg protein kJ^-1 digestible energy, respectively. Conclusions: Information developed is of high significance for optimizing growth potential by making better utilization of nutrient at 26 ℃ and, to develop effective management strategies for mass culture of this highly preferred fish species.

• Archives of Pharmacal Research
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• 제10권3호
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• pp.193-196
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• 1987

Protein methylation occurs ubiquitously in nature and involves N-methylation of lysine, arginine, histidine, alanine, proline and glutamine, O-methylesterfication o dicarboxylic acids, and S-methylation of cysteine and methionine. In nature, methylated amino acids accur in highly specialized proteins such as histones, flagella proteins, myosin, actin, ribosomal proteins. hn RNA-bound protein, HMG-1 and HMG-2 protein, opsin, EF-Tu, EF-$1\alpha$, porcine heart citrate synthase, calmodulin, ferredoxin, $1\alpha$-amylase, heat shock protein, scleroderma antigen, nucleolar protein C23 and IF-3l.

• BMB Reports
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• 제33권6호
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• pp.427-439
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• 2000

The activity of the phagocyte respiratory burst oxidase is regulated by complex and dynamic alterations in protein-protein interactions that result in the rapid assembly of an active multicomponent NADPH oxidase enzyme on the plasma membrane. While the enzymatic activity has been studied for the past 20 years, the past decade has seen remarkable progress in our understanding of the enzyme and its activation at the molecular level. This article describes the current state of knowledge, and proposes a model for the mechanism by which protein-protein interactions regulate enzyme activity in this system.

• Journal of Nutrition and Health
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• 제6권2호
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• pp.1-16
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• 1973

Some effects of dietary conditions on the metabolism of nucleic acid and protein in organs of the Albino Rats have been studied. The young rats to be examined were fed on the control diet and the diets deprived of one component among protein, carbohydrate, and lipid, such as protein free diet (PF: 432 kcal/100g) carbohydrate free diet (CF: 432kcal/100g), and lipid free diet (LF: 392kcal/100g) for three, seven, and fifteen days, respectively. The contents of DNA and RNA in the liver and the brain, and also those of protein-nitrogen(PN) and nonprotein-nitrogen (NPN) in the live, the brain, and the serum have been measured. The results are as followe: 1. The contents of DNA per gram of liver were increased by feeding on protein free diet. It is concluded that the critical factor for the result is not the increase in the rates of DNA syntheses, but the decrease in the turnover rates of DNA. 2. The metabolism of DNA in the liver showed the normal status by feeding on carbohydrate free diet. On the other hand, the rates of DNA syntheses were increased by feeding on lipid free diet. 3. The rates of DNA syntheses in the brain were decreased by feeding on the unbalanced diet, such as protein free, carbohydrete free, and lipid free diet. 4. In the liver and the brain, the rates of DNA syntheses were decreased by feeding on protein free diet. But the rates showed the normal status by feeding on the carbohydrate free diet, and also showed the similar metabolism to that in the case of the control group by feeding on lipid free diet. 5. In the liver, the rates of protein syntheses were decreased, whereas the contents of nonprotein-nitrogen were increased by feeding on protein free diet. 6. In the liver and the brain, the protein syntheses showed the more increasing rates than the rates in the case of the control diet by feeding on lipid free diet. 7. In the serum, the contents of protein did not change in a short period, also the insufficient feeling on protein was examined. It is clear that in the liver the rates of protein syntheses are decreased and the rates of protein catabolism are increased, since the rates of nucleic acid syntheses are decreased by feeding on the protein free diet. On the other hand, it is considered that in the brain the turnover rates of protein does not have correlation with the rates of nucleic acid syntheses, also these are decreased by feeding on protein free diet. And also it is believed that the phenomena of homeostasis for carrying the normal metabolism of nucleic acid and protein in the liver and the brain are operated in a short period as possible, by feeding on carbohydrate free and lipid free diets.

• BMB Reports
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• 제43권1호
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• pp.17-22
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• 2010

In this study, a novel member of BTB-kelch proteins, named KBTBD7, was cloned from a human embryonic heart cDNA library. The cDNA of KBTBD7 is 3,008 bp long and encodes a protein product of 684 amino acids (77.2 kD). This protein is highly conserved in evolution across different species. Western blot analysis indicates that a 77 kD protein specific for KBTBD7 is wildly expressed in all embryonic tissues examined. In COS-7 cells, KBTBD7 proteins are localized to the cytoplasm. KBTBD7 is a transcription activator when fused to GAL4 DNA-binding domain. Deletion analysis indicates that the BTB domain and kelch repeat motif are main regions for transcriptional activation. Overexpression of KBTBD7 in MCF-7 cells activates the transcriptional activities of activator protein-1 (AP-1) and serum response element (SRE), which can be relieved by siRNA. These results suggest that KBTBD7 proteins may act as a new transcriptional activator in mitogen-activated protein kinase (MAPK) signaling.