• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.143-151
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• 1998

Protein -surfactant interactions have been investigate by measuring ζ-potential of $\beta$-lactoglobulin-coated emulsion droplets and $\beta$-lactoglobulin in solution in the rpesenceof surfactant, with particular emphasis on the effect of protein heat treatment(7$0^{\circ}C$, 30min). When ionic surfactant (SDS or DATEM) is added to the protein solution, the ζ-potential of the mixture is found to increase with increasing surfactant concentration, indicating surfactant binding to the protein molecules. For heat-denatured protein,it has been observed that the ζ-potential tends to be lower than that of the native protein. The effect of surfactant on emulsions is rather complicated .With SDS, small amounts of surfactant addition induce a sharp increase in zeta potential arising from the specific interaction of surfactant with protein. With further surfacant addition, there is a gradual reductio in the ζ-potential, presumably caused by the displacement of adsorped protein (and protein-surfactant complex) from the emulsion droplet surfac by the excess of SDS molecules. At even higher surfactant concentrations, the measured zeta potential appears to increase slightly, possibly due to the formation of a surfactant measured zeta potential appears to increase slightly, possibly due to the formation of surfactant micellar structure at the oil droplet surface. This behaviour contrastswith the results of the corresponding systems containing the anionic emulsifier DATEM, in which the ζ-potential of the system is found to increase continuously with R, particularly at very low surfactant concentration. Overall, such behaviour is consisten with a combination of complexation and competitive displacement between surfactant and protein occurring at the oil-water interface. In addition, it has also been found that above the CMC, there is a time-dependent increase in the negative ζ-potential of emulsion droplets in solutions of SDS, possibly due to the solublization of oil droplets into surfactant micelles in the aqueous bulk phase.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.874-880
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• 1996

The effects of an anabolic steroid, nandrolone phenylpropionate(NPP), on body weight gain and body protein, and muscle protein metabolism were inestigated in adrenocorticotrophic hormone(ACTH)-treated male and female rats. Daily injections of 100ug/day of ACTH for 7-8 days caused a cessation of growth in females and a net loss of body weight in males which were associated with significant reductions in body protein content. However, food intake was not affected by ACTH in either sex. The weight, protein content and fractional rate of protein synthesis, measured in vivo, of gastrocnemius muscle were all significantly reduced in both sexes. NPP at a dose of 4mg/kg body weight prevented the reduction in body weight gain in ACTH-treate females but not in males. However, boy protein content was increased by NPP in both sexes which was associated with increases in the weight, protein content and fractional rate of protein synthesis of gastrocnemius muscle. ACTH treatment caused a marked increase in plasma concentrations of corticosterone in both sexes. NPP suppressed much of the increases in corticosterone concentrations in both sexes. The results of the present study suggest that NPP exerts at least part of its anabolic effect by reducing plasma concentrations of catabolic glucocorticoid hormones, through suppressing the response of the adrenals to ACTH.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.243-250
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• 2008

A calmodulin-dihydrofolate reductase (DHFR) sandwich fusion protein was generated by insertion of calmodulin into the $\beta$-bulge region of DHFR to observe the effects of structurally constraining the calmodulin structure. The calcium binding properties of the sandwich protein were almost identical to calmodulin. Similar to calmodulin ($10.7 {\mu}M$), the sandwich protein bound four equivalents of calcium, with half saturation ($K_{0.5}$) observed at a [$Ca^{2+}$] of $8{\mu}M$. However, nicotinamide adenine dinucleotide (NAD) kinase activation property of the sandwich protein was lower than that of calmodulin. The sandwich protein activated NAD kinase, but to only half of the level obtained with calmodulin. The K 0.5 for both calmodulin and the sandwich protein were approximately the same (1-2 nM). Methylation analyses of the sandwich protein show that insertion of calmodulin into DHFR results in a large decrease in methylation. The $V_{max}$ observed with the sandwich protein (95 nmole/min/ml) was only 22% of the value observed with calmodulin (436 nmol/min/ml) in the presence of calcium. Addition of trimethoprim to the reaction significantly inhibited the observed methylation rate. Overall, the data suggest that the insertion of calmodulin into the DHFR structure has little effect on calcium binding by the individual lobes of calmodulin, but may constrain the lobes in a manner that results in altered interaction with the calmodulin-dependent proteins, and severely perturbed the methyltransferase recognition site.

• Journal of Aquaculture
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• v.12 no.2
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• pp.137-143
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• 1999

The effects of dietary protein level on growth, feed utlization and liver size were studied with juvenile haddock (Melanogrammus aeglefinus) of 6.88$\pm$0.54 g (mean$\pm$SD). Five isoenergetic diets containing 44.4 to 64.7% protein were fed to triplicate groups of 50 fish in a flow-through system for 6 weeks. All fish showed a relative increase of more than 300% in final weight. There were, however, no significant differences (P>0.05) in weight gain (16.1 to 17.3 g) and specific growth rate (2.9 to 3.0) among fish groups. A higher protein diets resulted in a lower feed intake. Feed: gain ratio linearly improved (P<0.05) when protein level increased from 44.4 to 59.7%. The lowest protein efficiency ratio was observed in fish fed the highest protein diet. Hepatosomatic index of fish significantly decreased from 10.7 to 7.3% with an increase in protein level. Results from this study suggest that haddock could grow well even when fed the diet with protein lower than 44.4%.

• Ocean and Polar Research
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• v.25 no.3
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• pp.269-275
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• 2003

Effects of different operating factors including superficial air velocity (SAV), hydraulic residence time (HRT), protein concentration, and foam overflow height on protein removal by a foam fractionator in simulated seawater aquaculture system were investigated. This experiment was conducted on batch and consecutive modes at different combinations of the affecting factors. The foam fractionator had a diameter of 20cm and a height of 120cm and the experiment was conducted with synthetic wastewater. In 5 consecutive trials, protein concentrations in culture tank water decreased faster when the foam fractionator was operated at higher SAVs and lower HRTs. In batch trials, protein removal rates increased with an increase in SAV but decreased with an increase in URT. Higher protein concentrations in the bulk solution resulted in higher protein removal rates. Protein concentrations in the collected foam condensates increased but the foam overflow rates decreased with the increase of foam overflow heights. The results of this experiment indicate that foam fractionation would be an effective way for protein removal in seawater aquaculture systems and the performance of the foam fractionator depends largely on the operating parameters, especially SAV.

• Journal of Microbiology
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• v.44 no.2
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• pp.145-154
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• 2006

Heterotrimeric G proteins (G proteins) are conserved in all eukaryotes and are crucial components sensing and relaying external cues into the cells to elicit appropriate physiological and biochemical responses. Basic units of the heterotrimeric G protein signaling system include a G protein-coupled receptor (GPCR), a G protein composed of ${\alpha},\;{\beta},\;and\;{\gamma}$ subunits, and variety of effectors. Sequential sensitization and activation of these G protein elements translates external signals into gene expression changes, resulting in appropriate cellular behaviors. Regulators of G protein signaling (RGSs) constitute a crucial element of appropriate control of the intensity and duration of G protein signaling. For the past decade, G protein signaling and its regulation have been intensively studied in a number of model and/or pathogenic fungi and outcomes of the studies provided better understanding on the upstream regulation of vegetative growth, mating, development, virulence/pathogenicity establishment, and biosynthesis of secondary metabolites in fungi. This review focuses on the characteristics of the basic upstream G protein components and RGS proteins, and their roles controlling various aspects of biological processes in the model filamentous ascomycete fungus Aspergillus nidulans. In particular, their functions in controlling hyphal proliferation, asexual spore formation, sexual fruiting, and the mycotoxin sterigmatocystin production are discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.41-47
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• 1995

This experiments was designed to evaluated the chemical components and nutrition of Aspergillus fumigatus cells. This dried fungal mycellia was consist of crude protein 48.5%, crude lipid 2.9%, carbohydrate 44.7% and total ash 3.4%, respectively. The major fatty acid of total lipid were 27.9% of linoleic acid, 24.6% of oleic acid, 15.4% of palmitic acid and 10.6% of linolenic aicd. Amino acid analysis indicated that the protein was rich in aspartic acid, glutamic acid, leucine, lysine but poor in cystein, methionine, histidine. The fungal cake of Aspergillus fumigatus, when dried and specially processed, has been found to serve as a source of protein in place of soybean meal in the diet of experimental mice. Animal were fed a control diet first, and an incease in weight proved the formulation to be satisfactory. At the end of a 30-day period, the experimental mice showed increases in weight comparable to those of the control animals. The net protein efficiency ratio for the control diet was 3.42$\pm$0.15 and the fungal protein and succinylated fungal protein with DL-methionine they were 3.12$\pm$0.39 and 2.98$\pm$0.06 respectively. This supports the view that dried and succinylated fungal protein can be substituted as a protein source.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.62-65
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• 2002

We have previously shown that the addition of silkworm hemolymph to a culture medium increases the longevity of insect and mammalian cells by inhibiting apoptosis. This indicates that the component which inhibits apoptosis is contained in the silkworm hemolymph, The apoptosis-inhibiting component was isolated from silkwonn hemolymph and characterized in our previous study. A database search using the N-terminal amino acid sequence of this component as a template resulted in a 95% homology with a low molecular weight lipoprotein, the so called ’30K protein' of unknown function. In this study, the 30K protein gene was expressed in mammalian and insect cells to confirm the apoptosis-inhibiting effect. The overexpression of 30K protein in mammalian cell inhibited the staurosporin-induced apoptosis by the prevention of the activation of caspase 3. Using an Autographa californicanuclear polyhedrosis virus (AcNPV) system, the 30K protein was overexpressed also in insect cells. The expression of the 30K protein increased the longevity of baculovirus-infected insect cells by inhibiting apoptosis. These results suggest that the 30K protein is a novel anti-apoptotic protein.

• Molecules and Cells
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• v.46 no.12
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• pp.757-763
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• 2023

In this study, we examine whether a change in the protein levels for FOP in Ankyrin repeat and SAM domain-containing protein 1A (ANKS1A)-deficient ependymal cells affects the intraflagellar transport (IFT) protein transport system in the multicilia. Three distinct abnormalities are observed in the multicilia of ANKS1A-deficient ependymal cells. First, there were a greater number of IFT88-positive trains along the cilia from ANKS1A deficiency. The results are similar to each isolated cilium as well. Second, each isolated cilium contains a significant increase in the number of extracellular vesicles (ECVs) due to the lack of ANKS1A. Third, Van Gogh-like 2 (Vangl2), a ciliary membrane protein, is abundantly detected along the cilia and in the ECVs attached to them for ANKS1A-deficient cells. We also use primary ependymal culture systems to obtain the ECVs released from the multicilia. Consequently, we find that ECVs from ANKS1A-deficient cells contain more IFT machinery and Vangl2. These results indicate that ANKS1A deficiency increases the entry of the protein transport machinery into the multicilia and as a result of these abnormal protein transports, excessive ECVs form along the cilia. We conclude that ependymal cells make use of the ECV-based disposal system in order to eliminate excessively transported proteins from basal bodies.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.428-432
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• 1991

This study was carried out to investigate the effect of NaCl, pH and phosphate on the functional properties of a mixed system of plasma protein and myofibrillar proteins. The solubility of plasma protein, myofibrillar protein and the mixture (plasma+myofibrillar protein) increased according to the increase of NaCl concentration ($0{\sim}4%$) and pH $pH4{\sim}8$). The solubility, emulsifying activity and capacity of the mixture were lower than those of plasma protein, whereas higher than those of myofibrillar protein. The gel strength of the mixture and myofibrillar protein showed a significant increase when NaCl concentration was increased from 2 to 3%. The gel strength of myofibrillar protein increased about four times when 0.3% polyphosphate added to the sample containing 2% NaCl, whereas the moisture loss of the mixture and myofibrillar protein decreased significantly. The gel strength of plasma protein, myofibrillar protein and the mixture increased slightly at $3{\sim}5%$ protein concentration, whereas the gel strength of those increased significantly as the protein concentration increased from 5 to 9%.