• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.263-271
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• 1980

Detoxified and deallergenized castor bean protein isolate was prepared from defatted castor bean pomace for use in animal feedstuffs and human foods. Succinylation and acetylation of the ${\varepsilon}-amino$ groups of the protein improved markedly the water solubility of the protein at $pH\;7{\sim}8$. The results of the amino acid analysis of the protein isolate revealed that the sulfur-containing amino acids and L-lysine were limiting amino acids and that succinylation and acetylation caused some little loss of the amino acid content. The L-methionine enriched plastein was synthesized from the protein isolate or the acylated protein isolates and DL-methionine ethyl ester by one step process with papain. By this method the extent of incorporation of L-methionine was about 50%. Pepsin hydrolyzed both unmodified and modified protein isolates at the same rate (about 92%). Tryptic hydrolysis, however, was less for the succinylated protein isolates (about 42%) and less for the acetylated protein isolates (about 26%). The protein efficiency ratio of L-methionine enriched protein isolate (about 2.5 weight %) was 90% that of reference casein. The protein efficiency ratio values of succinylated (88%) and acetylated (84%) protein isolate were 55 and 69% of reference casein, respectively.

• Korean Journal of Poultry Science
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• v.12 no.1
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• pp.17-24
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• 1985

In order to investigate an effect of non-protein nitrogen on the biological utilization of protein, hatched single comb White Leghorn male chicks were fed for the first 8 days with a commercial chicks mash, next 6 days with protein-free diet and subsequent 6 days with protein-free diets and protein diets containing 10.59% of crude protein supplemented with 0, 0.5, 1.0 and 1.5%, respectively. During experimental feeding period, chicks fed protein-free diets had intaked gradually lower feed and had shown a similar body weight loss though urea contents were increased. When birds fed protein diets, body weight gain and feed intake were not different among birds fed the graded levels of urea although feed conversions were shown a highering tendency along with increasing urea contents. According as supplemented urea were increased, protein efficiency ratio f (PER) and net protein ratio (NPR) were increased in chicks fed protein-free diets, which were shown a lowering trend in chicks fed protein diets. Effect of supplemented urea on the urinary excretion of uric acid were not found in birds fed protein-free diets, while which were increased in birds fed protein diets with the increase of urea contents. Urea addition did not affect the excretion of total creatine in birds fed protein-free or protein diets. Excretion of ammonia was jogjered in order to increasing level of urea in birds fed protein-free diets, but which were not found any particular effect in birds fed protein diets. Also urea excretion were gradually increased with the increasing contents of urea in protein-free and protein diets. Nitrogen balance of birds fed protein-free diets were minus values, which were increased with increasing urea contents in diets. When birds fed protein diets, nitrogen balance and urinary nitrogen excretion was highered and fecal nitrogen excretion were not altered as urea levels of diets increased. Digestibility of urea nitrogen supplemented in protein-free diets were lowered along with increasing contents of urea, but biological value(BV) and net protein utilization(NPU) was found a highering tendency in birds fed protein-free diet containing 1.5% of urea. When birds fed with protein diets, digestibility, BV and NPU of protein were found a highering trend in birds fed protein diets added with 0.5% of urea.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.1
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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.

• Journal of Life Science
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• v.8 no.1
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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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• v.36 no.3
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• pp.172-177
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• 1993

To extract insoluble proteins from sesame meal residue by microorganism, the sesame meal residue was treated with crude enzyme solution of Bacillus sp. CW-1121. The foaming capacity of salt soluble protein was quite lower than that of water soluble protein and the foaming stability of salt soluble protein decreased abruptly in 10 min., while it sustained for 30 min in case of water soluble protein. Emulsion capacities of all the protein fractions showed minimum value near isoelectric point of protein and salt soluble protein had lower emulsion capacities than that of water soluble protein. The emulsion stability of the protein was relatively stable for 30 min at $80^{\circ}C$. Oil and water absorption capacities of salt soluble protein were higher than those of water soluble protein.

• Fisheries and Aquatic Sciences
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• v.23 no.1
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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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• v.10 no.3
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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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• v.33 no.6
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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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• v.6 no.2
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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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• v.43 no.1
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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.