• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.468-474
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• 1986

The emulsifying properties of soy protein isolate were measured at various conditions, and the relationships between the emulsifying properties and solubility, viscosity, hydrophobicity, protein adsorption, the tension at water-oil interface were investigated. The emulsifying properties are minimum at the isoelectric point(pI), and the effect of pH parallels its effect on protein solubility. The emulsifying activity is increasing up to $50^{\circ}C$ and then is somewhat decreasing above that temperature, while the emulsion stability is continuously decreasing. Except for phosphates, the salts cause the decrease of the emulsifying properties. The hydrophobicity is increasing as the temperature increases and decreasing somewhat as pH gets lower. However, it is increasing substantially at pH below the pI. The maximum protein adsorption at the water-oil interface is 0.78, 0.47, and $0.33mg/m^2$ at pH 2, 7, and 4, respectively. The tension at water-oil interface is 19.76 dyne/cm in the absence of soy protein, whereas it is decreasing to 11.45-18.08 dyne/cm in the presence of the protein.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.93-104
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• 2011

Two hepcidin paralogs (ojhamp1 and ojhamp2) were isolated and characterized from a euryhaline Javanese ricefish (Oryzias javanicus: Beloniformes). The ojhamp1 cDNA encoded 90 or 91 amino acids (aa) of a typical HAMP1 preproprotein. This preproprotein is believed to cleave and yield the 66 or 67 aa-proprotein, followed by the 26 aa-mature peptide, composed of 8 conserved cysteine residues and the QSHL amino terminal motif. The ojhamp2 cDNA encoded 89 aa of HAMP2 preproprotein, cleaved to yield a 65 aa proprotein, and subsequently the 25 aa-mature peptide. The mature OJHAMP1 possessed a cationic isoelectric point (pI), whereas OJHAMP2 had an anionic charge. At the genomic level, both ojhamp1 and ojhamp2 share a conserved tripartite structure (three exons interrupted by two introns) with other vertebrate hepcidin genes. However, the ojhamp1 was shown to exist as two distinct mRNA species, encoding 90 or 91 aa, due to alternative splicing at the junction site between intron I and exon II. Both ojhamp1 and ojhamp2 transcripts were detected in a wide range of tissue types with varying levels of basal expression, although the highest expression was observed in the liver for both isoforms. Transcriptional response to bacterial challenge using Edwardsiella tarda showed that ojhamp1 was moderately upregulated in the liver but remained unchanged in the kidney. However, the ojhamp2 was significantly suppressed in both the kidney and liver, suggesting a potential diversification between the two paralogs.

• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.

• Journal of Pharmaceutical Investigation
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• v.39 no.6
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• pp.423-429
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• 2009

Liposomes have been used as one of the efficient carriers for drug delivery. In this study, anionic liposomes of which surface was modified by using both electrostaic interaction between anionic liposomes and cationically charged BSA molecules at lower pH than isoelectric point (pI) of BSA and denaturation of the BSA-coated liposomes by thermal treatment. The thermally denatured BSA-coated liposomes (DBAL) had mean particle diameter of 125.2${\pm}$1.7 nm and zeta potential value of -22.4${\pm}$4.5 mV. Loading efficiency of model drug, doxorubicin (DOX), into liposomes was 83.0${\pm}$2.6%. Results of in vitro stability study of DBAL in blood plasma showed that the mean particle diameter of DBAL 400 did not increase in blood plasma and adsorption of plasma protein was much less than plain or anionic liposomes. Intracellular uptake of DBAL 400 evaluated by confocal microscopy observation was higher than that of PEG liposomes.

• Journal of Sericultural and Entomological Science
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• v.6
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• pp.18-27
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• 1966

This treatise was sat up as a basic study of the artificial diets of silk worm, both nursed and wild, by storing the natural leaves in defarmentizing solution and the results obtained were as followings. 1. Defarmentizer C, a kind of defarmentizer, was developed by the author in order to store any natural diet by soaking them in the solution. 2. The defarmentizer was workable for aerophobic bacteriums, but was not effectable for aerophilic bacteriums or fungus. 3. The defarmentized diet could feed silk worm during winter season. 4. The storing method has found the importance of growthness of the diet leaves and the perfect riped leaves were found as the best condition for the purpose. 5. The perfect riped leaves were softened properly during the soaking to be fed for silk worm. 6. The defarmentizing solution has held almost the same pH value of protein isoelectric point so that the protein extraction be ceased during the soaking process. 7. The utilization of defarmentizer has found an economical value. 5. The analytical results of various wild plant leaves were found to be usable as the artificial diet mixture for general silkworm.

• Journal of Radiation Industry
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• v.2 no.3
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• pp.97-104
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• 2008

Cinnamate-4-hydroxylase (C4H) is a key enzyme of phenylpropanoid pathway, which leads a variety of secondary metabolites to participate in differentiation and protection of plant against environmental stresses. In this study, we isolated a full-length cDNA of the C4H gene from a black raspberry (Rubus occidentalis L.), using a reverse transcriptase-PCR and rapid amplification of the cDNA ends (RACE)-PCR. The full-length cDNA of the RocC4H gene contained a 1,515 bp open reading frame (ORF) encoding a 504 amino acid protein with a calculated molecular weight of about 57.9 kDa and an isoelectric point (pI) value of 9.1. The genomic DNA analysis revealed that RocC4H gene had three exons and two introns. By multiple sequence alignment, RocC4H protein was highly homologous with other plant C4Hs, and the cytochrome P450-featured motifs, such as the heme-binding domain, the T-containing binding pocket motif (AAIETT), the ERR triad, and the tetrapeptide (PPGP) hinge motif, were highly conserved. Southern blot analysis revealed that RocC4H is a single copy gene in R. occidentalis.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.39-45
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• 1993

The effects of enzymatic modification with pepsin and actinidin was studied on molecular weight distributions and functional properties of hydrolysates from soy protein isolate (SPI) differing in degree of hydrolysis. The hydrolyzed SPI by pepsin showed 41.5% degree of hydrolysis after 5 min, and maximum hydrolysis was obtained after 2 hours. Actinidin hydrolyzed SPI 26.71% degree after 1 hour. On SDS-PAGE, native SPI showed 9 distinguishable bands on SDS-PAGE gel. Pepsin treated SPI showed one broad band in the lower part of gel. This band was shifted further to the bottom of the gel and became faint as hydrolysis time increased. While actinidin treated SPI showed different SDS-PAGE pattern from pepsin. However PAGE patterns were similar with pepsin and actinidin treated groups. With pepsin treatment, solubility of SPI distinctively increased around isoelectric point(pI). Emulsifying activity (EA) and emulsifying stability (ES) showed marked increase over pH range of $3.0{\sim}8.0$. 5 min modified group had most excellent foam expansion (FE). Foam stability (FS) was increased as pepsin treatment time increased at pI. With actinidin treatment, solubility was increased. 60 min modified SPI had the most effective EA at pH 4.5. However ES was not effected by actinidin treatment. 5 min modified group was most effect in FE. FS was higher at alkaline pH.

• Korean journal of food and cookery science
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• v.9 no.1
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• pp.43-51
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• 1993

Buckwheat protein isolate was tested for the effects of pH, addition of sodium chloride and heat treatment on solubility, emulsion capacities, emulsion stability, surface hydrophobicity, foam capacities and foam stability. The solubility of buckwheat protein isolate was affected by pH and showed the lowest value at pH 4.5, the isoelectric point of buckwheat protein isolate. The solubility significantly as the pH value reached closer to either ends of the pH, i.e., pH 1.0 and 11.0. The effects of NaCl concentration on solubility were as follows; at pH 2.0, the solubility significantly decreased when NaCl was added; at pH 4.5, it increased above 0.6 M; at pH 7.0 it increased; and at pH 9.0 it decreased. The solubility increased above $80^{\circ}C$, at all pH ranges. The emulsion capacity was the lowest at pH 4.5. It significantly increased as the pH approached higher acidic or alkalic regions. At pH 2.0, when NaCl was added, the emulsion capacity decreased, but it increased at pH 4.5 and showed the maximum value at pH 7.0 and 9.0 with 0.6 M and 0.8 M NaCl concentrations. Upon heating, the emulsion capacity decreased at acidic pH's but was maximised at pH 7.0 and 9.0 on $60^{\circ}C$ heat treatment. The emulsion stability was the lowest at pH 4.5 but increased with heat treatment. At acidic pH, the emulsion stability increased with the increase in NaCl concentration but decreased at pH 7.0 and 9.0. Generally, at other pH ranges, the emulsion stability was decreased with increased heating temperature. The surface hydrophobicity showed the highest value at pH 2.0 and the lowest value at pH 11.0. As NaCl concentrationed, the surface hydrophobicity decreased at acidic pH. The NaCl concentration had no significant effects on surface hydrophobicity at pH 7.0, 9.0 except for the highest value observed at 0.8 M and 0.4 M. At all pH ranges, the surface hydrophobicity was increased, when the temperature increased. The foam capacity decreased, with increased in pH value. At acidic pH, the foam capacity was decreased with the increased in NaCl concentration. The highest value was observed upon adding 0.2 M or 0.4 M NaCl at pH 7.0 and 9.0. Heat treatments of $60^{\circ}C$ and $40^{\circ}C$ showed the highest foam capacity values at pH 2.0 and 4.5, respectively. At pH 7.0 and 9.0, the foam capacity decreased with the increased in temperature. The foam stability was not significantly related to different pH values. The addition of 0.4 M NaCl at pH 2.0, 7.0 and 9.0 showed the highest stability and the addition of 1.0 M at pH 4.5 showed the lowest. The higher the heating temperature, the lower the foam stability at pH 2.0 and 9.0. However, the foam stability increased at pH 4.5 and 7.0 before reaching $80^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.275-282
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• 1997

The prcx.iuction of extracellular 1,4-${\beta}$-glucanase by Cellulomonas sp. CS1-1 on microcrystalline cellulose, sigmacell was maximal after 5-day cultivation as 280 units/mL, which was three times higher than the level produced on carboxymethyl cellulose. A carboxymethyl cellulase containing the carbohydrate of 8.2% was purified from the culture filtrate by successive procedures of column chromatographies. Purification factor was calculated as 22-folds with the specific carboxymethyl cellulase activity of 31.9 units/mg. The molecular weight and isoelectric point of the purified enzyme were 54,000 and pI 5.4, respectively. The optimal pH and temperature were 6.0 and $45^{\circ}C$, and the enzyme was stable between pH 6.5 and 7.5 and below $50^{\circ}C$. The estimated Km and Vmax were 10 mg/mL and $6.25{\mu}mol/min$ for carboxymethyl cellulose and 30.3 mg/mL and $2.85{\mu}mol/min$ for sigmacell, respectively. The enzyme was partially inhibited by $Ag^+$, $Zn^{+{+}}$, $Fe^{+{+}}$ and EDTA, while completely inhibited by $Cd^{+{+}}$ and $Hg^{+{+}}$ at 1 mM concentration.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.731-738
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• 2003

The technique known as proteomics is useful for characterizing the protein expression pattern of a particular tissue or cell type as well as quantitatively identifying differences in the levels of individual proteins. In present study, we carried out the comparative expression patterns of white and red muscles. We used the two-dimensional electrophoresis(2-DE) for analyzing the protein expression. Proteins isolated from porcine white and red muscles were separated by 12% poly-acrylamide gel and then were detected by coomassie blue and silver staining. More than 600 protein spots were detected on each 2-DE gel. By visual analysis of the stained gel, five proteins were identified to be differentially expressed in the white vs red muscle. By database searching based on the molecular weights and pI(isoelectric point) of the five proteins, three of them were found to be most close to troponin I, T and myoglobin. However, further researche is needed for identification and functional analysis of the unidentified proteins. In conclusion, we found five proteins, which are differentially expressed in the white vs red muscle. The functional analysis of the differentially expressed proteins will provide valuable information on biochemical characteristics of the muscle type.