• 한국당과학회:학술대회논문집
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• 2006.11a
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• pp.35-36
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• 2006

• KSBB Journal
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• v.7 no.4
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• pp.302-307
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• 1992

Protein phosphatase 2A was obtained from a cytosolic fraction of bovine brain homogenate. The phosphatase activity using phosphorylated histone Hl as substrate was suppressed in the presence of liposomes composed of dipalmitoylphosphatidylcholine(DPPC) or the mixture of phosphatidylserine and DPPC. The binding of protein phosphatase to liposome was indicated by the facts that the phosphatase activity of the supernatant of protein phosphatase/multilayer vesicle mixture was decreased with increasing amount of liposome, and that [$^{125}I$]-labeled protein phosphatase was coeluted with liposome. However, the affinity of the protein for phospholipid membrane was not so high. On the other hand, okadaic acid and liposome reduced the phosphatase activity synergistically, which means that okadaic acid binds neither to lipid membrane nor to the membrane-associated phosphatase, The inhibitory effect of liposome was, therefore, ascribed to association of the protein phosphatase 2A with the lipid bilayer membrane.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2002.06a
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• pp.5-23
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• 2002

Motivation: Protein-protein interaction plays a critical role in the biological processes. The identification of interacting proteins by bioinformatical methods can provide new lead In the functional studies of uncharacterized proteins without performing extensive experiments. Results: Protein-protein interactions are predicted by a computational algorithm based on the weighted scoring system for domain interactions between interacting protein pairs. Here we propose potential interaction domain (PID) pairs can be extracted from a data set of experimentally identified interacting protein pairs. where one protein contains a domain and its interacting protein contains the other. Every combinations of PID are summarized in a matrix table termed the PID matrix, and this matrix has proposed to be used for prediction of interactions. The database of interacting proteins (DIP) has used as a source of interacting protein pairs and InterPro, an integrated database of protein families, domains and functional sites, has used for defining domains in interacting pairs. A statistical scoring system. named "PID matrix score" has designed and applied as a measure of interaction probability between domains. Cross-validation has been performed with subsets of DIP data to evaluate the prediction accuracy of PID matrix. The prediction system gives about 50% of sensitivity and 98% of specificity, Based on the PID matrix, we develop a system providing several interaction information-finding services in the Internet. The system, named PreDIN (Prediction-oriented Database of Interaction Network) provides interacting domain finding services and interacting protein finding services. It is demonstrated that mapping of the genome-wide interaction network can be achieved by using the PreDIN system. This system can be also used as a new tool for functional prediction of unknown proteins.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.313-318
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• 2005

Estimating the reliability of protein-protein interaction data sets obtained by high-throughput technologies such as yeast two-hybrid assays and mass spectrometry is of great importance. We develop a maximum likelihood estimation method that uses both protein localization and gene expression data to estimate the reliability of protein interaction data sets. By integrating protein localization data and gene expression data, we can obtain more accurate estimates of the reliability of various interaction data sets. We apply the method to protein physical interaction data sets and protein complex data sets. The reliability of the yeast two-hybrid interactions by Ito et al. (2001) is 27%, and that by Uetz et at.(2000) is 68%. The reliability of the protein complex data sets using tandem affinity purification-mass spec-trometry (TAP) by Gavin et at. (2002) is 45%, and that using high-throughput mass spectrometric protein complex identification (HMS-PCI) by Ho et al. (2002) is 20%. The method is general and can be applied to analyze any protein interaction data sets.

• Journal of Nutrition and Health
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• v.28 no.8
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• pp.782-790
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• 1995

The longitudinal changes in protein secretion from 27 lactating women(primiparae = 10, multiparae=17) and protein intake of infants have been studied from 0.5 to 6 months postpartum in Chungju and Anseong area. The protein contents o breast milk in primiparae appeared significantly higher than in multipaae at 0.5 and 1 month postpartum. The protein secretion of primiparae and multiparae was not significantly different. In breast-feeding period, there was a tendency that protein secretion from 0.5 to 2 months postpartum was higher than thereafter. Average protein intake of boys from milk from 0.5 to 6 months postpartum was significantly higher than that of girls(p<0.05), because volume of milk intake of boys was much more than that of girls. In the amount of protein intake per infant weight, there was no significant difference between boys and girls. Protein intakes per infant weight decreased during lactation. Mean energy consumption of lactating women was 2,327㎉/day, which was 93.1% of recommended energy allowance for Koreans. Mean dietary protein consumption of lactating women was 81g/day, which was 101.3% of recemmended protein allowance for Koreans. Energy ratio of carbohydrate : protein : lipid was appeared to 68.8 : 13.9 : 17.3.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.341-347
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• 1991

It was reported that protein carboxymethylation is involved in amylase secretion of parotid gland by isoproterenot. It was also suggested that a small part of the total cellular protein carboxymethylation is directly involved in pancreatic enzyme secretion. On the contrary, other authors reported that there is no relationship between protein carboxymethylation and secretion in pancreas and parotid gland. In recent study, it was proposed that a methyl acceptor protein plays a limited modulatory role in the coupling of cytosolic $Ca^{++}$ accumulation and exocytosis. In this study, the effects of cholinergic and adrenergic agents on the activities of protein methylase II in pancreatic tissues were examined to test the relationship between protein methylation and pancreatic secretion. The results are as follows. The activity of amylase was slightly increased at the concentration of $10^{-5}$ M of isoproterenol and norepinephrine. The activities of protein methylase I and II were decreased by isoproterenol and norepinephrine, but the activities of protein methylase III were hardly changed. The cholinergic stimulants acetylcholine and carbachol at a concentration of $10^{-5}$ M increased the activities of protein methylase I and decreased the activitiy of protein methylase III compared with control.

• Journal of Crop Science and Biotechnology
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• v.10 no.3
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• pp.133-140
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• 2007

Protein characteristics of Korean wheat were evaluated to determine the effects of protein content and quality on processing and textural properties of white salted noodles compared to US wheat flours with various wheat classes and commercial flours for making noodles. Protein quality parameters, which were independent of protein content and included SDS sedimentation volume with constant protein weight, mixograph mixing time and proportion of 50% 1-propanol insoluble protein, of Korean wheat flours with 2.2+12 subunits in high molecular weight glutenin subunit compositions were comparable to those of commercial flours for making noodles. Parameters related to noodle making, including optimum water absorption, thickness and color of noodle dough sheet, correlated with protein content and related parameters, including SDS sedimentation volume with constant flour weight, mixograph water absorption and gluten yield. No significant relationship was found in protein parameters independent of protein content. Hardness of cooked noodles from Korean wheats was lower than that of US wheat flours compared to similar protein content of commercial noodle flours. Adhesiveness, springiness and cohesiveness of cooked noodles from Korean wheats were similar to US wheat flours. Hardness of cooked noodles correlated with protein content and related parameters.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.163-166
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• 2016

Hydrophobicity is the key concept to understand the water plays in protein folding, protein aggregation, and protein-protein interaction. Traditionally, the hydrophobicity of protein is defined based on the scales of the hydrophobicity of residue, assuming that the hydrophobicity of free amino acids is maintained. Here, we explore how the hydrophobicity of constituting amino acids in protein rely on the protein context, in particular, on the total charge and secondary structures of a protein. To this end, we calculate and investigate the hydration free energy of three short proteins based on the integral-equation theory of liquids. We find that the hydration free energy of charged amino acids is significantly affected by the protein total charge and exhibits contrasting behavior depending on the protein total charge being positive or negative. We also observe that amino acids in the ${\beta}-sheets$ display more enhanced the hydrophobicity than amino acids in the loop, whereas those in the ${\alpha}-helix$ do not clearly show such a tendency. And the salt-bridge forming amino acids also exhibit increase of the hydrophobicity than that with no salt bridge. Our results provide novel insights into the hydrophobicity of amino acids, and will be valuable for rationalizing and predicting the strength of water-mediated interaction involved in the biological activity of proteins.

• Journal of Aquaculture
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• v.13 no.1
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• pp.1-7
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• 2000

The effect of various dietary protein levels on growth and body composition of young common carp raised from 56 g to 170 g in recirculating system was investigated for 15 weeks when they were fed to visual satiety three times daily. Five experiemtal diets were formulated to contain 40, 35, 30, 25 and 21% protein levels and 3.56, 3.59. 3.63, 3.66 and 3.69 kcal/g diet GE levels respectively. Mean survival rates of the fish fed the 40, 35, 30 and 25% protein diets were not different but sig-nificantly higher than that of the fish fed the 40, 35, 30 and 25% protein diets were not different but sig-nificantly higher than that of o the fish fed the 21% protein diet(P<0.05) Weight gain (g/tank) of common carp fed the 30% protein diet was the best. However weight gain of the fish fed the 25, 30, 35 and 40% protein diets were not different but significantly better than that of the fish fed the 21% protein diet. Feed efficiency ratio of the 21% protein diet was significantly lower (P<0.05) than for other groups of diets which were not different among them. Protein efficiency ratio for the 21% protein diet was significantly lower (P<0.05) than for other groups of diets which were not different among them(P>0.05) Dietary protein level had no effect on hemoglobin content in the fish(P>0.05) Crude protein contents of whole body of the fish fed the 35 and 40% protein diets were significantly higher than that of the fish fed the 21$$\mid$% or 25% protein diet(P<0.05) Body crude lipid contents of the fish fed the 21 and 25% protein diets were significantly higher than that of the fish fed the 30% or 35% protein diet. Crude ash contents of the fish fed the 35 and 40% protein diets were significantly higher than that of the fish fed the 21% or 25% protein diet(P<0.05) Moisture content of the fish fed the 35% protein diet was significantly higher than that of the fish fed the 21% protein diet(P<0.05) In considering growth performance of common carp and efficiency of diet dietary protein level could be lowered up to 25% without the reduction of young common carp production in recirculating system.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.333-339
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• 2010

The objectives of this study were to use the NRC-2001 model and DVE/OEB system to model potential nutrient supply to ruminants and to compare frost damaged (also called "frozen" wheat with normal wheat. Quantitative predictions were made in terms of: i) Truly absorbed rumen synthesized microbial protein in the small intestine; ii) Truly absorbed rumen undegraded feed protein in the small intestine; iii) Endogenous protein in the digestive tract; iv). Total truly absorbed protein in the small intestine; and v). Protein degraded balance. The overall yield losses of the frozen wheat were 24%. Results showed that using the DVE/OEB system to predict the potential nutrient supply, the frozen wheat had similar truly absorbed rumen synthesized microbial protein (65 vs. 66 g/kg DM; p>0.05), tended to have lower truly absorbed rumen undegraded feed protein (39 vs. 53 g/kg DM; p<0.10) and had higher endogenous protein (14 vs. 9 g/kg DM; p<0.05). Total truly absorbed protein in the small intestine was significantly lower (89 vs. 110 g/kg DM, p<0.05) in the frozen wheat. The protein degraded balance was similar and both were negative (-2 vs. -1 g/kg DM). Using the NRC-2001 model to predict the potential nutrient supply, the frozen wheat also had similar truly absorbed rumen synthesized microbial protein (average 56 g/kg DM; p>0.05), tended to have lower truly absorbed rumen undegraded feed protein (35 vs. 48, g/kg DM; p<0.10) and had similar endogenous protein (average 4 g/kg DM; p>0.05). Total truly absorbed protein in the small intestine was significantly lower (95 vs. 108 g/kg DM, p<0.05) in the frozen wheat. The protein degraded balance was not significantly different and both were negative (-16 vs. -19 g/kg DM). In conclusion, both models predict lower protein value and negative protein degraded balance in the frozen wheat. The frost damage to the wheat reduced nutrient content and availability and thus reduced nutrient supply to ruminants by around 12 to 19%.