• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.455-460
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• 1991

In order to identify hard distinct 12 fish species(shiba shrimp Metapenaeus joyneri, fleshy shrimp Penaeus orientalis, ridgetail prawn Palaemon carinicauda, yellow croaker Pseudosciaena manchurica, croaker Niber albiflora, Colichthyes fragilis, brown sole Limanda herzensteini, frog flounder Pleuronichthys cornutrs, Areliscus rhomaleus, stone flounder Kareius bicoloratus, harvest fish Pampus argenteus, flag fish Goniistius zonatus) by seeing with naked eye in Kunsan coastal area, sarcoplasmic protein in the supernatant was used for isoelectric focusing. For getting supernatant, fish muscle tissue was blended with two times deionized water and centrifuged (at $4^{\circ}C$, 12,000rpm for 15min). Isoelectric focusing of sarcoploasmic protein carried out on a LKB Multiphor II using polyacrylamide gel plate (2mm thickness, pH $3.5~10^{\circ}C$, pH 5~8 gradient, at $10^{\circ}C$ for 1.5, 3 hours). In case of uncertain protein pattern, pH gradient was modified to narrow pH gradiet, and excuted 2-D electrophoresis using conventional polyacrylamide gel electrophoresis. Most of fishes except yellow croaker and Collichthyes fragilis were distingushed by isoelectric focusing. The protein maps of 2-D electrophoresis for analyzing two protein bands at aimilar positions(pH 5, 6) between the two fish species showed the diffeences of the estimated molecular weights, 11,700(pH5.0) and 87,000(pH6.0)

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.524-527
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• 1992

Synechococcus sp. cyanophage was isolated from Baekwoon reservoir located in KyonggiDo. The cyanophage was purified by employing ultrafiltration. differential centrifugation. and sucrose density gradient centrifugation. Electron microscopic observation indicated that the sizes of its isometric head and contractile tail are 89 nm and] II nm. respectively. which means that the isolated cyanophage is included in the group. Myoviridae. The cyanophage maintained the stability of more than 50 percent from $20^{\circ}C$ to $40^{\circ}C$ and from pH 5 to 8. and had the maximal infectivity at $30^{\circ}C$ and pH 9 implying its ecological significance.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.545-551
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• 2010

Hydrophobically monoendcapped poly(sodium acrylate)s formed hydrophobic microdomains in water. This was concluded on poly(sodium acrylate)s with a linear $C_{12}$-alkyl chain attached specifically at the end of the polymer. There was no well defined CMC (critical micelle concentration), but rather a gradual transition from a micelle free solution to a micelle solution. Steady state fluorescence spectroscopy indicates that the micro domains are rather hydrophobic. At pH 5 in the abscence of salt and at pH 9 in the prescence of 1 M sodium citrate the CAC (critical aggregation concentration) was in the range of 0.1 to 2.4 mM. However at pH 5 there was a linear increase in the transition concentration with a head-group size due to an increase in steric and electrostatic repulsions between polymer main chains. At pH 9 in the abscence of salt the transition concentration was in the range of 1 to 80 mM. For the larger polymers there was a effect which consisted of a concentration gradient of sodium counterion toward the hydrophobic domain. The effect was larger for the larger polymers because of the higher total sodium concentration and the less steep counterion concentration gradient.

• Journal of Plant Biology
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• v.24 no.4
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• pp.171-179
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• 1981

The membrane-bound ATPases were separated on sucrose gradient from corn roots and characterized by pH optima, sensitivity to monovalent salt, Km and Vmax. The pH optima for the activity of all the ATPases associated with 13, 000g pellet and 13, 000~80, 000g pellet were 5 and 9, respectively. The ATPases in Fractions B and C of the 13, 000 g pellet were more active at pH 5 than pH 9. While, in the case of Fractions D, E and F, they were reverse. The activities of the ATPase in Fractions A and C of the 13, 000~80, 000 g pellet were greater at pH 5 than pH 9. On the other hand, the ATPases in Fractions B, D, E, and F were more active at pH 9 than pH 5. The optimum concentraction of ATP for the assay was about 3 to 5 mM. The Km's for the membrane-bound ATPases in 13, 000g pellet and in 13, 000~80, 000 g pellet were 0.25 mM. While Vmax values for 13, 000g pellet were from 8.0 to 12.5 $\mu$M Pi/mg protein/hr. according to pH values, those for 13, 000~80, 000 g pellet were from 35.7 to 55.6 $\mu$M Pi/mg protein/hr. Activities of the membrane-bound ATPases in both 13, 000 g pellet and 13, 000~80, 000 g pellet were stimulated with increasing the concentration of $K^+$.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.117-121
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• 2004

Soluble proteins of silkworm hemolymph were investigated by means of isoelectric focusing (IEF). The protein spectra during ontogenesis of races and inter-races hybrids kept in Bulgaria was studied. A total of 51 protein bands in the hemolymph from fourth larval instar to imago were ascertained. Stage specific expression was established. The specific expression of some protein bands in the individual spectra manifest phenotype of gene determinate polymorphism (HP F, HP J, HP K, HP L, HP Q - in the zone with pH gradient 3.5-6.2 and HP K, HP L, HP N, HP P, HP T - in the zone with pH gradient 9.5 - 6.2). Breed specific expression was observed. On the basis of the obtained results, it was established that the investigated breeds are heterogeneous and the isoelectric focusing method is successful when specifying the inner-race and inter-race polymorphism in silkworm.

• Journal of the Korean Mathematical Society
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• v.44 no.3
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• pp.585-603
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• 2007

The author studies the local $H\ddot{o}lder$ convergence of the solution to an evolution equation of p-Ginzburg-Landau type, to the heat flow of the p-harmonic map, when the parameter tends to zero. The convergence is derived by establishing a uniform gradient estimation for the solution of the regularized equation.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.49-60
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• 1991

The change of the acridine orange absorbance was used to monitor the formation and/or dissipation of a pH gradient in microvillous membrane vesicles (MVV) isolated from human term placenta. Under $Na^+$ efflux conditions, an acidification of the intravesicular space occured and it was completely inhibited by 0.1 mM amiloride. Under $K^+$ efflux conditions, an acidification of the intravesicular space occured and it was potentiated by valinomycin or FCCP. An inwardly directed chloride gradient also induced a minor intravesicular acidification, but it was not observed in voltage-clampled MVV. The initial rate of the dissipation of a pH gradient was accelerated by pulse injections of $Na^+$ in a saturable manner and $Li^+$ could replace $Na^+$. The kinetic parameter of $Na^+$ in placental $Na^+/H^+$ exchange was similar to that of renal $Na^+/H^+$ exchange. Amiloride was a inhibitor of directly coupled $Na^+/H^+$ exchange and its $IC_{50}$ in placental MVV was about 14-fold higher than that in renal brush border membrane. These results indicate that $Na^+/H^+$ exchanger exists in human placental MVV and that its kinetic characteristics is similar to that of renal $Na^+/H^+$ exchanger but its pharmacological characteristics is different. In placental MVV $K^+,\;H^+$, and, relatively minor chloride conductances are present. The magnitude of $Cl^-/OH^-$ exchange, even though it exists, seems to be smaller than that of $Na^+/H^+$ exchange.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.1
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• pp.47-53
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• 2003

An experimental study on the chromatographic separation of maltopentaose from a mixture, including glucose, maltose, maltotriose, and maltopentaose, was carried out in a nonionic polymeric sorbent column while varying the operating conditions, such as the solution pH, buffer contents, and isopropyl alcohol (1PA) concentration. Unlike the pH and buffer contents, the IPA concentration had a Significant impact on the single component chromatograms for maltopentaose. The retention times of the maltooligosaccharides with the nonionic polymeric sorbent Sp207 were in the following order: glucose < maltose < maltotriose < maltopentaose. From the experimental binary, ternary, and quaternary chromatograms, gradient chromatographic separation with a changing IPA concentration as a function of time was required to obtain high-purity maltopentaose and reduce the elution time.

• KSBB Journal
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• v.16 no.6
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• pp.533-537
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• 2001

${\alpha}$-lactalbumin and ${\beta}$-lactoglobulin in whey proteins were separated by high performance membrane chromatography (HPMC). The separation mechanism involved anion-exchange, and the stationary phase was anion CIM (Convective Interaction Media) DEAE, QA disk and cation exchanger SO$_3$(16${\times}$3 mm). Two types of mobile phase were used, buffer A (20 mM Tris-HCI, pH 7.3) and buffer B(buffer A + 1 M NaCl), As the amount of NaCl dissolved in buffer linearly increased, which enabled a gradient elution mode. The optimum mobile phase and operating condition (Buffer A/Buffer B = 100/0 - 30/70 vol%, gradient time 1 min, 30/70 - 10/90 vol.%, gradient time 2 min) were experimentally determined. In this experimental condition, ${\alpha}$-lacta1bumin, ${\beta}$-lactoglobulin were separated within 5 min at a mobile phase flow rate of 4 mL/min.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.76-84
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• 2013

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at $4^{\circ}C$ and $10^{\circ}C$. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at $4^{\circ}C$. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at $4^{\circ}C$ and $10^{\circ}C$. Lc. gelidum was detected as the dominant LAB at $4^{\circ}C$ in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At $4^{\circ}C$, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased.