• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1274-1281
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• 2011

Dietary protein restriction affects lipid metabolism in rats. This study was performed to determine the effect of a low protein diet on hepatic lipid metabolism and insulin sensitivity in growing male rats. Growing rats were fed either a control 20% protein diet or an 8% low protein diet. Feeding a low protein diet for four weeks from 8 weeks of age induced a fatty liver. Expression of acetyl-CoA carboxylase, a key lipogenic enzyme, was increased in rats fed a low protein diet. Feeding a low protein diet decreased very low density lipoprotein (VLDL) secretion without statistical significance. Feeding a low protein diet down-regulated protein expression of microsomal triglyceride transfer protein, an important enzyme of VLDL secretion. Feeding a low protein diet increased serum adiponectin levels. We performed glucose tolerance test (GTT) and insulin tolerance test (ITT). Both GTT and ITT were increased in protein-restricted growing rats. Our results demonstrate that dietary protein restriction increases insulin sensitivity and that this could be due to low-protein diet-mediated metabolic adaptation. In addition, increased adiponectin levels may influences insulin sensitivity. In conclusion, dietary protein restriction induces a fatty liver. Both increased lipogenesis and decreased VLDL secretion has contributed to this metabolic changes. In addition, insulin resistance was not associated with fatty liver induced by protein restriction.

• 대한수의학회지
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• 제30권2호
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• pp.187-192
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• 1990

돼지로부터 분리한 Staphylococcus hyicus subsp hyicus 489주의 protein A 존재여부와 함량을 indirect hemagglutination 및 enzyme-linked immunosorbent assay(ELISA)법으로 조사하였다. Indirect hemagglutination text에 의하여 cell-bound protein A 및 extracellular protein A 보유균은 489주 중 각각 87.7% 및 36.0%로 나타났다. ELISA법에 의한 이들 균의 protein A함량 측정에서 전균주의 extracellular protein A는 1ng/ml미만이었으며, cell-bound protein A함량은 대부분의 균주에서 1ng/ml 미만이었고 11주가 25~108ng/ml 수준이었다.

• 한국동물학회지
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• 제33권2호
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• pp.141-151
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• 1990

Raf protein kinases and protein kinase C는 세포질내 serine/threonine-specific protein에 속한다. 그리고 기능적인 구조와 세포내의 분포 양상은 서로 비슷하다. Raf family oncogene를 발현시키는 a-raf와 c-raf protein kinase에 대한 antibodies로써 남생이 대뇌의 raf protein kinase의 분포를 조사하였다. 일반적으로 raf protein kinase는 제한된 지역에서 즉,general pallium,hippocampal formation, pdmordiuin hippocampi,nucleus of lateral olfactory tract, basal amygdaloid nucleus와bed of stria terminalis에 나타났으며, c-raf protein kinase의 면역학적 labeling은 a-raf보다 그 범위가 넓었다. 그렇지만 labeling되는 intensity는 오히려 a-raf보다 낮았다. 그런데 a-raf에서 가장 명확한 좋은 예는 basal amygdaloid nucleus내의 구형모양의 세포인데, 이 세포는 세포질이 매우 강하게 labeling되어 지므로 ring모양과 같이 나타났다. 특히 c-raf는 protein kinase C 가 많이 나타나는 pyramidal 세포나 Purkinje세포에 많이 존재하는 것을 볼 때 protein kinase에 의하여 활성화되는 myc와 서로 상협작용을 유도한다고 제안하는 바이다.

• Journal of Nutrition and Health
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• 제26권9호
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• pp.1033-1048
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• 1993

This study was designed to describe the effect of the protein quality at different intake level of protein on the protein metabolism in the whole body of growing pigs with a simulation model. Varying to the protein level in feeds, four simulations were conducted. The feed protein level, represented as proportions of digestible protein to the metabolic energy (DP/ME, g/MJ), were 6-8, 11-13, 17-19, and 23-25 DP/ME, respectively. Two protein quality and six weeks of growth time were used at each simulation. The objective function for the simulations was protein deposition in the whole body, which was calculated from the experimental results. The parameters in the simulation were determined by the parameter estimation technique. The results obtained from the simulation were as follows: The protein synthesis and breakdown rates(g/day) in the whole body was increased with the increase of protein quality only at lower or required level of protein intake. They showed a parallel behavior in the course of growth, irrespective of quality and level of feed protein intake. The simulated protein deposition and protein synthesis showed a linear relationship between them at different protein quality and level. The affinity parameter showed a linear relationship between them at different protein quality and level. The affinity parameter showed that arginine, tryptophan and isoleucine were more efficient in the stimulation ofbody protein synthesis. Lysine and phenylalanine+tyrosine were less efficient. The oxidation parameter showed that histidine, pheyalanine+tyrosine were less efficient. The oxidation parameter showed that histidine, phenyalanine+tyrosine, and methionine+cystine were oxidized in larger magnitude than lysine and threonine. The oxidation parameter of most amino acids increased with the increase of protein intake beyond the requirement level, but not any more at highest protein intake level. Finally it was found that the improvement of feed protein quality at the lower or required level of protein intake increase protein deposition through a parallel increase of protein synthesis and breakdown.

• 한국식품영양과학회지
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• 제28권1호
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• pp.178-190
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• 1999

This study was conducted to develop a simulation model for the growth dynamics of pigs and to describe quantitatively protein deposition depending on the amino acid composition of feed protein. In the model it is assumed that the essential processes that determine the utilization of feed protein in the whole body are protein synthesis, breakdown of protein, and oxidation of amino acid. Besides, it is also assumed that occurrence of protein deposition depends on genetic potential and amino acid composition of feed protein. The genetic potential for the protein deposition is the maximum capacity of protein synthesis, being dependent on the protein mass of the whole body. To describe the effect of amino acid composition of feed on the protein deposition, a factor, which consist of ten amino acid functions and lie between 0 and 1, is introduced. Accordingly a model was developed, which is described with 15 flux equations and 11 differential equations and is composed of two compartments. The model describes non linear structure of the protein utilization system of an organism, which is in non steady state. The objective function for the simulation was protein deposition(g/day) cal culated according to the empirical model, PAF(product of amino acid functions) of Menke. The mean of relative difference between the simulated protein deposition and PAF calculated values, lied in a range of 11.8%. The simulated protein synthesis and breakdown rates(g/day) in the whole body showed a parallel behavior in the course of growth.

• BMB Reports
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• 제33권2호
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• pp.188-192
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• 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 Microbiology
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• 제44권5호
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• pp.508-514
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• 2006

In this study, the double-stranded DNA-dependent activities of Deinococcus radiodurans RecA protein (Dr RecA) were characterized. The interactions of the Dr RecA protein with double-stranded DNA were determined, especially dsDNA-dependent ATP hydrolysis by the Dr RecA protein and the DNA strand exchange reaction, in which multiple branch points exist on a single RecA protein-DNA complex. A nucleotide cofactor (ATP or dATP ) was required for the Dr RecA protein binding to duplex DNA. In the presence of dATP, the nucleation step in the binding process occurred more rapidly than in the presence of ATP. Salts inhibited the binding of the Dr RecA protein to double-stranded DNA. Double-stranded DNA-dependent ATPase activities showed a different sensitivity to anion species. Glutamate had only a minimal effect on the double-stranded DNA-dependent ATPase activities, up to a concentration of 0.7 M. In the competition experiment for Dr RecA protein binding, the Dr RecA protein manifested a higher affinity to double-stranded DNA than was observed for single-stranded DNA.

• 동아시아식생활학회지
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• 제5권3호
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• pp.385-394
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• 1995

Our previous reports on the effect of dietary protein on methanethiol, ethacrynic acid, bromobenzene and carbon tetrachloride metabolism were overall reviewed. The methanethiol, ethacrynicacid and bromobenzene treated rats showed the more severe liver damage in those fed a low protein diet than those fed a standard protein diet. These xenobiotics treated rats showed the lower content of hepatic glutathione and its conjugated enzyme, glutathione S-transferase activities in those fed a low protein diet than those fed a standard protein diet. In case of carbon tetrachloride treated rats, the liver damage was more reduced in rats fed a low protein diet than those fed a standard protein diet. Concomitantly the hepatic cytochrome P-450 content, and its decreasing rate to the control were lower in rats fed a low protein diet than those fed a standard protein diet.

• Nutritional Sciences
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• 제1권1호
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• pp.3-7
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• 1998

The aim of the present investigation was to see whether an anabolic steroid, nandrolone phenylpropionate (NPP), exerts protienanabolic effects under such adverse nutritional conditions as protein deficiency and protein-energy malnutrition in male rats. feeding on a low-protein (8% casein) diet resulted in a marked reduction in body weight gain that was associated with reductions in body protein and protein content of gastrocnemius muscle. Administration of NPP (4 mg/kg body weight) did not alter muscle and body protein depletion induced by a low-protein diet. 50% food restriction caused reductions in body protein and in protein content of gastrocnemius muscle. These reductions were partially prevented by NPP (4 mg/kg body weight). Food restriction did not affect plasma concentration of corticosterone, insulin, or tetosterone plus dihydrotestosterone. On the other hand, neither plasma concentration of corticosterone nor insulin were affected by NPP. The present results show that anabolic steroids do not express anabolic effects under conditions of protein deficiency, but in protein-energy malnutrition, anabolic steroids exert their anabolic effects even in male rats.

• Macromolecular Research
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• 제11권1호
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• pp.53-61
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• 2003

A molecular-thermodynamic model is developed for the salt-induced protein precipitation. The protein molecules interact through four intermolecular potentials. An equation of state is derived based on the statistical mechanical perturbation theory with the modified Chiew's equation for the fluid phase, Young's equation for the solid phase as the reference system and a perturbation based on the protein-protein effective two body potential. The equation of state provides an expression for the chemical potential of the protein. In a single protein system, the phase separation is represented by fluid-fluid equilibria. The precipitation behaviors are simulated with the partition coefficient at various salt concentrations and degree of pre-aggregation effect for the protein particles. In a binary protein system, we regard the system as a fluid-solid phase equilibrium. At equilibrium, we compute the reduced osmotic pressure-composition diagram in the diverse protein size difference and salt concentrations.