• Journal of Nutrition and Health
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• v.30 no.6
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• pp.605-613
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• 1997

This study was to investigate interaction between dietary protein and Ca levels in Ca metabolism and renal function in osteporosis rats. Five week-old female rats were fed a low Ca diet for 4 weeks after ovariectomy operation to establish rat models of osteoporosis. The ovariectomized osteoporosis rats were divided into six groups and were fed experimental diets which contained two levels of protein, normal (20%) and high(40%) , and three levels of Ca, low (0.06%), normal (0.47%) and high(0.94%) for 4 weeks , respectively. The ovaricetmized rat model of osteoporosis showed a remarkable decrease in serum Ca concentration, fresh weight and breaking force of femur, Ca and P contents of femur, and apparent absorption and retention of Ca. The supplementations of Ca and P contents of femur, and apparent absorption and retention of Ca. The supplementations of Ca at the dietary levels of normal and high levels significantly enhanced Ca bioavailability shown in the above experimental rat models of osteoporosis, regardless of dietary protein levels ; whereas the rats which were fed the low Ca diet demonstrated rather a decrease in its bioavailability. Irrespectively of the dietary Ca levels, the rats which were fed high protein diet exhibited an increase in kidney weight, urinary Ca, volume and hydroxyproline, and glomerular filtration ratio(GFR). The results show that dietary protein and calcium levels affect the renal function and Ca metabolism independently, while the interaction between protein and calcium have not been shown.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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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.

• Biomedical Science Letters
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• v.14 no.2
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• pp.77-81
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• 2008

Testis brain RNA-binding protein (TB-RBP) is a DNA/RNA binding protein. TB-RBP is mainly expressed in testis and brain and highly conserved protein with several functions, including chromosomal translocations, DNA repair, mitotic cell division, and mRNA transport, stabilization, and storage. In our previous study, we identified TB-RBP as an interacting partner for the catalytic subunit $(C{\alpha})$ of protein kinase A(PKA) and verified their interaction with several biochemical analyses. Here, we confirmed interaction between $C{\alpha}$. and TB-RBP in mammalian cells and determined the effect of $C{\alpha}$. on the function of TB-RBP. The activation of $C{\alpha}$. increased the TB-RBP function as a DNA-binding protein. These results suggest that the function of TB-RBP can be modulated by PKA and provide insights into the diverse role of PKA.

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1072-1079
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• 1996

This study was performed to elucidate the mechanism of dietary protein level on renal function through lipid and eicosanoids metabolism. Male rats of 337.8$\pm$5.7g body weight were undergone unilateral nephrectomy or sham-operation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein) diet groups and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. Serum total lipid, cholesterol and HDL-cholesterol of rats in 15% and 40% casein groups were higher than those of 8% casein group. But serum triglyceride was affected neither by uninephrectomy nor by dietary protein level. Serum thromboxane(TX) B2 and 6-keto prostaglandin F1$\alpha$ increased with increasing dietary protein level. Serum prostaglandin(PG) E2 was not affected by uninephrectomy nor by dietary protein level. Urinary PGE2 and TXB2 excretion tended to be lower in uninephrectomized groups. Renal tissue concentration of TXB2 was lower in uninephrectomized groups and in high protein group. These results suggest the possibility that the effects of dietary protein level on renal function could be due to changes in lipid and eicosanoids metabolism.

• BMB Reports
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• v.33 no.3
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• pp.195-201
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• 2000

A human gene has been reported that may encode the enzyme acetohydroxyacid synthase. Previously this enzyme was thought to be absent from animals although it is present in plants and many microorganisms. In plants, this enzyme is the target of a number of commercial herbicides and the use of these compounds may need to be reassessed if the human enzyme exists and proves to be susceptible to inhibition. Here we report the construction of several plasmid vectors containing the cDNA sequence for this protein, and their expression in Escherichia coli. High levels of expression were observed, but most of the protein proved to be insoluble. The small amounts of soluble protein contained little or no acetohydroxyacid synthase activity. Attempts to refold the insoluble protein were successful insofar as the protein became soluble. However, the refolded protein did not gain any acetohydroxyacid synthase activity. In vivo complementation tests of an E. coli mutant produced no evidence that the protein is active. Incorrect folding, or the lack of another subunit, may explain the data but we favor the interpretation that this gene does not encode an acetohydroxyacid synthase.

• Macromolecular Research
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• v.15 no.7
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• pp.682-687
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• 2007

The equation of state developed herein is predicated on a hard-sphere reference with perturbations introduced via a potential function to account for electrostatic forces and for attraction between protein particles. During this process, the generalized Lennard-Jones (GLJ) pair potential function is employed. The GLJ pair potential function is employed to represent the protein-protein interaction in two-protein systems. Via the use of the relation between the equation of state and the chemical potential, the phase behavior in the aqueous two-protein system can be estimated. The partition coefficients can be obtained via these processes. The calculated values of the coefficients agree fairly well with the experimental data in the given pH and ionic strength range, with no additional adjustable model parameters.

• The KIPS Transactions:PartB
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• v.12B no.2 s.98
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• pp.209-214
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• 2005

The use of protein interaction data is highly reliable for predicting functions to proteins without function in proteomics study. The computational studies on protein function prediction are mostly based on the concept of guilt-by-association and utilize large-scale interaction map from revealed protein-protein interaction data. This study compares graph-based approaches such as neighbor-counting and $\chi^2-statistics$ methods using protein-protein interaction data and proposes an approach that is effective in analyzing large-scale protein interaction data. The proposed approach is also based protein interaction map but sequence similarity and heuristic knowledge to make prediction results more reliable. The test result of the proposed approach is given for KDD Cup 2001 competition data along with those of neighbor-counting and $\chi^2-statistics$ methods.

• The Korean Journal of Food & Health Convergence
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• v.4 no.4
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• pp.18-25
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• 2018

Proteins play a key role in many functions such as metabolic activity, differentiation, as cargos and cell fate regulators. It is necessary to know about the markers involved in male fertility in order to develop remedies for the treatment of male infertility. But, the role of the proteins is not limited to particular function in the biological systems. Some of the proteins act as ion channels such as catsper and proteins like Nanos acts as a translational repressor in germ cells and expressed in prenatal period whose role in male fertility is uncertain. Rbm5 is a pre mRNA splicing factor necessary for sperm differentiation whose loss of function results deficit in sperm production. DEFB114 is a beta defensin family protein necessary for sperm motility in LPS challenged mice where as TEX 101 is a plasma membrane specific germ cell protein whose function is not clearly known u to now. Gpr56 is another adhesion protein whose null mutation leads to arrest of production of pups in rats. Amyloid precursor protein role in Alzheimer's disease is already known but it plays an important role in male fertility also but its function is uncertain and has to be considered while targeting APP during the treatment of Alzheimer's disease. The study on amyloid precursor protein in male fertility is a novel thing but requires further study in correlation to alzheimer's disease.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.294-299
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• 2005

We have studied unbound docking for 12 protein-protein complexes using conformational space annealing (CSA) combined along with statistical pair potentials. The CSA, a powerful global optimization tool, is used to search the conformational space represented by a translational vector and three Euler amgles between two proteins. The energy function consists of three statistical pair-wise energy terms; one from the distance-scaled finite ideal-gas reference state (DFIRE) approach by Zhou and the other two derived from residue-residue contacts. The residue-residue contact terms describe both attractive and repulsive interactions between two residues in contact. The performance of the CSA docking is compared with that of ZDOCK, a well-established protein-protein docking method. The results show that the application of CSA to the protein-protein docking is quite successful, indicating that the CSA combined with a good scoring function is a promising method for the study of protein-protein interaction.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.259-271
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• 2008

We propose a protein function finding algorithm that is able to predict specific molecular function for unannotated proteins through domain analysis from protein-protein network. To do this, we first construct protein-protein interaction(PPI) network in Saccharomyces cerevisiae from MIPS databases. The PPI network(proteins; 3,637, interactions; 10,391) shows the characteristics of a scale-free network and a hierarchical network that proteins with a number of interactions occur in small and the inherent modularity of protein clusters. Protein-protein interaction databases obtained from a Y2H(Yeast Two Hybrid) screen or a composite data set include random false positives. To filter the database, we reconstruct the PPI networks based on the cellular localization. And then we analyze Hub proteins and the network structure in the reconstructed network and define structural modules from the network. We analyze protein domains from the structural modules and derive functional modules from them. From the derived functional modules with high certainty, we find tentative functions for unannotated proteins.