• 한국식품조리과학회지
• /
• 제24권3호
• /
• pp.304-311
• /
• 2008

This study examined Jeung-pyun(JP) Retrogradation in samples containing 3% whole protein, 7S protein, or 11S protein(w/w) that were stored at $4^{\circ}C$ for 6, 12, 24 and 72 hr. Rheometery and differential scanning calorimetry(DSC) were used in the analysis. The pH of the dough decreased during the fermentation process, but it increased after steaming. The JP prepared with soybean protein isolate(SPI) had higher pH than the control group. During storage the textural characteristics of the JP showed effects according to the additions of SPI. After 6 hr of storage, the JP samples containing soybean flour, whole protein, 7S protein, and 11S protein had lower hardness valuse. From 4 hr to 12 hr, higher springiness values were found in the samples containing whole protein, 7S protein and 11S protein. At 0 hr, the control group had the highest cohesiveness value, but after 24 hr it presented the lowest value. For gumminess, after 6 hr of storage, the control group offered the lowest value. Whereas after 12 hr of storage the whole protein group showed the highest value, and at 24 hr, the whole protein, 7S protein, and 11S protein groups had higher values. According to the DSC results, the 11S protein group had lower enthalpy values(${\bigtriangleup}H$) suggesting that adding 11S protein to JP might improve starch retrogradation. After 72 hr of storage, the control group had the highest onset temperature($T_{o}$) and peak temperature($T_{p}$) whereas the 7S and 11S protein JP samples had higher conclusion temperatures($T_{c}$). Therefore, based on the different analysis result between the control and treatment groups, the addition of SPI to Jp had effects on retrogradation.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
• /
• pp.175-176
• /
• 2003

Dietary protein is the most expensive component in flounder feed because of the high protein requirement of this species. The non-protein energy sources may also influence the protein utilization of fish. The inclusion of adequate levels of non-protein energy sources in diets can minimize use of protein as an energy source. Protein sparing effect by fat and carbohydrate has been studied in other fish. (omitted)

• Journal of Microbiology
• /
• 제37권2호
• /
• pp.90-96
• /
• 1999

The core protein of the hepatitis C virus (HCV) is a multifunctional protein. The HCV core protein was reported to regulate cellular gene expression and transform primary rat embryo fibroblast cells. However, the role of the core protein in the pathogenesis of HCV-associated liver diseases is not well understood. To investigate the functional role of the core protein in cytophathogenicity, we have constructed stable expression systems of full length or truncated HCV core protein lacking the C-terminal hyderophobic domains and established HepG2 cell clones constitutively expressing the core protein. The full length core protein was localized in the cytoplasm and the C-terminal truncated core protein was localized in the nucleus. HepG2 cells expressing nuclear, truncated core protein showed elevated cell death during cultivation compared to untransfected cells and full length core-expressing cells. In the treatment with bleomycin, both cell clones expressing full length or truncated core protein appeared to be more sensitive to blemoycin than the parental HepG2 cells. These results suggest that the core protein may play a role in HCV pathogenesis promoting apoptotic cell death of infected cells.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권1호
• /
• pp.133-140
• /
• 2005

Although amino acids are substrates for the synthesis of proteins and nitrogen-containing compounds, it has become more and more clear over the years that these nutrients are also extremely important as regulators of body protein turnover. The branched-chain amino acids (BCAAs) together or simply leucine alone stimulate protein synthesis and inhibit protein breakdown in skeletal muscle. However, it was only recently that the mechanism(s) involved in the regulation of protein turnover by BCAAs has begun to be defined. The acceleration of protein synthesis by these amino acids seems to occur at the level of peptide chain initiation. Oral administration of leucine to food-deprived rats enhances muscle protein synthesis, in part, through activation of the mRNA binding step of translation initiation. Despite our knowledge of the induction of protein synthesis by BCAAs, there are few studies on the suppression of protein degradation. The recent findings that oral administration of leucine rapidly reduced $N^{\tau}$-methylhistidine (3-methylhistidine; MeHis) release from isolated muscle, an index of myofibrillar protein degradation, indicate that leucine suppresses myofiblilar protein degradation. The details of the molecular mechanism by which leucine inhibits proteolysis is just beginning to be elucidated. The purpose of this report was to review the current understanding of how BCAAs act as regulators of protein turnover.

• Fisheries and Aquatic Sciences
• /
• 제18권3호
• /
• pp.265-271
• /
• 2015

A feeding trial of four dietary protein levels (20, 30, 40, and 50%) and two lipid levels (7 and 14%) with a factorial design was conducted to determine the optimal dietary protein and lipid levels for juvenile Israeli carp Cyprinus carpio. Triplicate groups of fish (average body weight, $1.3{\pm}0.02g$) were fed the experimental diets for 9 weeks. Survival of fish was not affected by either dietary protein or dietary lipid level. Weight gain and feed efficiency increased as dietary protein levels increased up to 40 and 50%, respectively. Weight gain was higher in fish fed the high-lipid diets with 20 and 40% protein content. Feeding efficiency increased as the dietary lipid level increased for the 30, 40, and 50% protein diets. Daily feed intake decreased with increasing protein level and the minimum feed consumption was observed in fish fed the 50% protein diet with 14% lipid content. Moisture and lipid contents of the whole body were affected by both dietary protein and lipid levels. The crude lipid content of fish fed the 14% lipid diet was higher than that of fish fed the 7% lipid diet at each protein level. The results of this study indicate that a diet containing 40% protein with 14% lipid content is optimal for the growth and effective protein utilization of juvenile Israeli carp.

• 한국식품영양과학회지
• /
• 제23권6호
• /
• pp.894-898
• /
• 1994

To evaluate an effect of dietary protein on the liver damage, the bromobenzene was intraperitoneally injected to the rats fed a low or high protein diet and then the liver weight per body weight and serum levels of alanine aminotransferase (ALT) activities were determined to demonstrate the differences in liver damage between the groups fed low or high protein diet. Hepatic aniline hydroxylase (AH), glutthione (GSH) content and glutathione s-transferase(GST) activity were also determined to clarify causes of liver damage between the two groups. Increases of liver weight per body weight and serum ALT activities were higher in brombenzene treated rats fed low protein diet than those fed high protein diet. The increasing rate of hepatic AH activity was higher in bromobenzne-treated rats fed low protein diet than that in those fed high protein diet. Furthermore , hepatic glutathione contents and GST activities in bromobenzene-treated rats were higher in rats fed high protein diet than those fed low protein diet. In case of control group, the heaptic glutathione content and GST activity were also higher in rats fed high protein diet than those fed low protein diet.

• BMB Reports
• /
• 제33권2호
• /
• pp.188-192
• /
• 2000

Recombinant protein G has been utilized in the purification of antibodies from various mammalian species based on the interaction of antibodies with protein G. The interaction between immunoglobulin and protein G may not be restricted to the Fc protion of antibodies, as many different $F(ab)_2$ or Fab fragments can also bind to protein G. I found both FAb $F(ab)_2$ of 145-2C11, a hamster anti-mouse $CD3{\varepsilon}$ antibody, bound to the protein G-sepharose. Interestingly, Fab and $F(ab)_2$ of 145-2C11 did not bind to the protein A-sepharose. The binding of Fab and $F(ab)_2$ of 145-2C11 to protein G provided a useful method to remove proteases, chopped fragments of the Fc region, and other contaminating proteins. The remaining intact antibody in the protease reaction mixture can be removed by using a protein A-sepharose, because the Fab and $F(ab)_2$ portions of 145-2C11 did not bind to protein A-sepharose. The specific binding of Fab and $F(ab)_2$ portions of 145-sC11 to a protein G-sepharose (though not to a protein A-sepharose) and binding of intact 145-2C11 to both protein A- and G-sepharose will be useful in developing an effective purification protocol for Fab and $F(ab)_2$ portions of 145-2C11.

• Journal of Nutrition and Health
• /
• 제44권4호
• /
• pp.338-343
• /
• 2011

This study assessed the current EAR, RDA, and AMDR for protein, which were set in 2005 and revised in 2010 as the DRIs for Koreans. A classical approach to establish the EAR for protein has been the nitrogen balance method. This method has practical limitations and problems in statistical analysis by giving over estimations of nitrogen balance. Thus, the present EAR for protein might be lower than the true requirement. Recent reevaluations of nitrogen balance studies by bilinear regression analysis and the IAAO method have indicated that the EAR of 0.66 g/kg bw/d should be increased by 39% to give 0.92 g/kg bw/d. The AMDR for protein in the Korean DRIs was set at 7-10%, which covers almost the entire population's protein intake. Since the 5th percentile of Korean protein intake is close to 10% of energy and due to the beneficial effects of protein beyond the maintenance of nitrogen equilibrium, the lower range of 7% needs to be increased up to 10%. For practical meal arrangement, 15% of energy as protein, which is close to the average protein intake of Koreans, seems to be proper, although the value is almost two times the EAR.

• 대한가정학회지
• /
• 제29권3호
• /
• pp.47-59
• /
• 1991

This study wa performed to investigate the effects of dietary protein and fiber on the lead and protein metabolism in lead poisoning rats. Seventy male rats of Sprague-Dawley strain weighing 172$\pm$2g were blocked into 14 gropus according to body weight. Protein(casein) was given at levels of 15 or 40%, and fibers(pectin, cellulose and CMC) were given at levels of 0, 4 or 10%. The results are summarized as follows: 1. Food intake, weight gain and food efficiency ratio(FER) in groups fed high protein diets were higher than those in low protein groups. Liver weight in groups fed no dietary fiber was higher than that of animals fed fiber. Kidney and femur weights were greater in high protein groups. Tibia and femur lengths, and tibia weight were not significantly different among groups. 2. Hemoglobin content and hematocrit values showed no significant differance with dietary factors. 3. Total protein contents of serum and liver showed no significant difference, but tended to increase with increasing dietary protein level. Both daily urinary and fecal nitrogen excretions in high protein groups were higher than those in low protein groups. Especially daily fecal nitrogen excretions in high dietary fiber groups were significantly high. Body nitrogen absorption rate was the highest in animals fed no fiber. 4. Pb levels in blood, liver, kidney and bone tended to decrease with high dietary protein and fiber levels. Especially Pb level of kidney was high in all groups. Daily urinary Pb excretion showed no significant difference with dietary factors, but fecal Pb excretion increased significantly in high protein and fiber groups.

• 대한기계학회논문집A
• /
• 제28권12호
• /
• pp.1997-2003
• /
• 2004

This paper presents a new method and an associated device, capable of detecting protein presence and size from the shift of the mechanical stiffness changing points due to the presence and size of proteins in a nano-gap actuator. Compared to the conventional resonant detection method, the present nanomechanical stiffness detection method shows higher precision for protein detection. The present method also offers simple and inexpensive protein detection devices by removing labeling process and optical components. We design and fabricate the nanomechanical protein detector using an electrothermal actuator with a nano-gap. In the experimental study, we measure the stiffness changing points and their coordinate shift from the devices with and without target proteins. The fabricated device detects the protein presence and the protein size of 14.0$\pm$7.4nm based on the coordinate shift of stiffness changing points. We experimentally verify the protein presence and size detection capability of the nanomechanical protein detector for applications to high-precision biomolecule detection.