• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.312-317
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• 1995

The polygalacturonase (PG) production in rotten apples by Botryosphaeria dothidea was purified by using gel filtration and ion exchange column chromatography, and the biochemical characters of PG were investigated. The purified PG appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with approximate molecular weight of 49 kilodalton (kDa). The molecular weight was equal to the native molecular weight estimated by gel filtration. The Km and Vmax values of PG were 0.51 mg/ml and 90.9 $\mu$M/min/ml, respectively. Optimum pH was 4.0~5.0, and the PG activity was stable from pH 5.0~10.0. Optimum temperature of the enzyme activity was 4$0^{\circ}C$. The PG activity was relatively stable at 2$0^{\circ}C$, but it was reduced 45% at 4$0^{\circ}C$ and completely inactivated at 8$0^{\circ}C$. The PG activity was considerably inhibited by Cu2+, Zn2+, SDS and EDTA, whereas it was not effected by Ca2+, K+, Mg2+ or Na+ ions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.728-735
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• 1995

The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2166-2171
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• 2007

In this paper, we proposed a Sequential Download System(SDS) to provide high steaming QoS in p2p network. SDS is able to receive a media file simultaneously from multiple source peer by download manager and deal with unexpected leave of source peer. Also It can provide stable streaming services with minimum buffering delay and manage request of other peer by memory map in process of downloading.

• BMB Reports
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• v.35 no.4
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• pp.364-370
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• 2002

The effect of sodium n-dodecyl sulphate (SDS) on hemoglobin autoxidation was studied in the presence of a 100mM phosphate buffer (pH 7.0) by different methods. These included spectorphotometry, fluorescence technique, cyclic voltametry, differential scanning calorimetry, and densitometry. Spectroscopic studies showed that SDS concentrations up to 1 mM increased deoxy-, decreases oxy-, and had no significant effect on the met- conformation of hemoglobin. Therefore, a SDS concentration up to 1 mM increased the deoxy form of hemoglobin as the folded, compact state and decreases the oxy conformation. The turbidity measurements and differential scanning calorimetry techniques indicated a more stable conformation for hemoglobin in the presence of SDS up to 1mM. Electrochemical studies also confirmed a more difficult oxidation under these conditions. The induction of the deoxy form in the presence of SDS was confirmed by densitometry techniques. The compact structure of deoxyhemoglobin blocks the formation of met-conformation in low SDS concentrations.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.58-68
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• 2012

An investigation was conducted on the enhancement of production and purification of an oxidant and SDS-stable alkaline protease (BHAP) secreted by an alkalophilic Bacillus horikoshii, which was screened from the body fluid of a unique Korean polychaeta (Periserrula leucophryna) living in the tidal mud flats of Kwangwha Island in the Korean West Sea. A prominent effect on BHAP production was obtained by adding 2% maltose, 1% sodium citrate, 0.8% NaCl, and 0.6% sodium carbonate to the culturing medium. The optimal medium for BHAP production contained (g/l) SBM, 15; casein, 10; $K_2HPO_4$, 2; $KH_2PO_4$, 2; maltose, 20; sodium citrate, 10; $MgSO_4$, 0.06; NaCl, 8; and $Na_2CO_3$, 6. A protease yield of approximately 56,000 U/ml was achieved using the optimized medium, which is an increase of approximately 5.5-fold compared with the previous optimization (10,050 U/ml). The BHAP was homogenously purified 34-fold with an overall recovery of 34% and a specific activity of 223,090 U/mg protein using adsorption with Diaion HPA75, hydrophobic interaction chromatography (HIC) on Phenyl-Sepharose, and ion-exchange chromatography on a DEAE- and CM-Sepharose column. The purified BHAP was determined a homogeneous by SDS-PAGE, with an apparent molecular mass of 28 kDa, and it showed extreme stability towards organic solvents, SDS, and oxidizing agents. The $K_m$ and $k_{cat}$ values were 78.7 ${\mu}M$ and $217.4s^{-1}$ for N-succinyl-Ala-Ala-Pro-Phe-pNA at $37^{\circ}C$ and pH 9, respectively. The inhibition profile exhibited by PMSF suggested that the protease from B. horikoshii belongs to the family of serine proteases. The BHAP, which showed high stability against SDS and $H_2O_2$, has significance for industrial application, such as additives in detergent and feed industries.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.177-182
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• 2006

Polyphenol oxidase (PPO) was isolated from the flesh of Fuji apples by DEAE-Cellulose, ammonium sulfate precipitation, phenyl-Sepharose CL-4B, and Sephdex G-100 chromatography. The molecular mass of the purified PPO was estimated to be 40 kDa by SDS polyacrylamide gel electrophoresis. With regard to substrate specificity, maximum activity was achieved with chlorogenic acid as substrate, followed by catechin and catechol whereas, there was no detectable activity with hydroquinic acid, resorcinol, or tyrosine as substrate. The optimum pH and temperature with catechol as substrate were 6.5 and $35^{\circ}C$, respectively. The enzyme was most stable at pH 6.0 and unstable at acidic pH. The enzyme was stable when it was heated to $45^{\circ}C$ but heating at $50^{\circ}C$ for more than 30 min caused 50% loss of activity. Reduced $ZnSO_4$, L-cystein, epigallocatechin-3-o-gallate (EGCG), and gallocatechin gallate (GCG) also inhibited activity.

• Applied Microscopy
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• v.30 no.2
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• pp.185-191
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• 2000

An unusually large protein complex was found in the cytosol of the hyperthmophilic archaeon. Thermococcus profundus. The purified protein was shown to be a homomultimer of 93 kDa subunit (P93 complex). The complex is extremely heat stable. During 12 hrs incubation with SDS (final concentration 1%) at $85^{\circ}C$, no changed structure could be observed. Electron image analysis of negatively stained showed that the complex has a single, stable characteristic view and a well-preserved core with threefold rotational symmetry. The periphery of the assembly is composed of a nebulose, possibly flexible, component. Based on the projected structure suggest the P93 complex from T. profundus is composed 24 homomultimer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4B
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• pp.377-382
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• 2011

In this study, hydrogen peroxide is stabilized in modified Fenton reaction to improve the soil remediation. Phenanthrene, which is the typical compound in PAHs, was spiked into soil samples to copy the original contaminated site. Anionic surfactant, SDS (Sodium dodecyl sulfate) was used for hydrogen peroxide stabilizer. 4 mM of Fe(II), 5~50 mM of SDS and 102.897 mM of $H_2O_2$ was injected into soil samples which is contaminated by 125 mg/kg of phenanthrene to analyze decomposition rate of phenanthrene in modified Fenton reaction. In condition which SDS was injected 30 mM, decomposition rate of phenanthrene has best efficiency as 95% and in condition which SDS was injected over 30 mM, decomposition rate is lower than SDS 30 mM because SDS enacted as scavenger in the system. Results which assess the change of hydrogen peroxide concentration after injecting hydrogen peroxide stabilizer showed that hydrogen peroxide concentration was 14.6995 mM so that is stabilized at Fe(II) 2 mM condition in 48 hours. On the other hand, hydrogen peroxide is not stable in Fe(III) condition. SDS concentration was fixed and iron concentration was changed 2~8 mM to find out optimize proportion between iron concentration and SDS concentration in modified Fenton reaction. Consequentially, in condition of which Fe(II) 4 mM and SDS 30 mM, reaction has the highest removal rate as 95%.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.822-827
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• 2000

Gamma irradiation was applied to reduce shrimp allergy. Shrimp heat-stable protein(HSP) and shrimp protein extract were gamma-irradiated at 1, 3, 5, 7 or 10 kGy in an aqueous state (1.0 mg/mL). The changes in allergenic and antigenic properties of protein extract and HSP resulted from gamma irradiation were monitored by ELISA with mouse mAb or human patients sera and immunoblotting. Conformational changes in irradiated HSP were measured by both GPC-HPLC and SDS-PAGE. The binding ability of shrimp allergic patients IgE to irradiated protein extract or irradiated heat-stable protein was dose-dependently reduced. When measured by gel permeation chromatography and sandwich ELISA, the amount of intact heat-stable protein in the irradiated solution was reduced by gamma irradiation depending upon the applied dose. SDS-PAGE showed that the main band disappeared and new bands appeared in a higher molecular weight zone. The results provide a new possibility to use irradiation process for reducing the allergenicity of shrimp.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.779-785
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• 1994

The interaction between the cationic dye, thionin(Th) and the anionic surfactant, sodium dodecyl sulfate (SDS) has been investigated by absorption spectra. As the temperature of surfactant solution was increased in premicellar range(S/D=10, 80, and 160) which was much lower than the critical micelle concentration(CMC), the increment or decrement of the molar extinction coeffecient ratio appeared. It was found that the most stable temperature range of the oligomer aggregate in Th-SDS system at S/D=160 was below $60^{\circ}C$. With increasing the concentration of inorganic salt and organic solvents in Th-SDS system, ${\alpha}$-band was increased, but ${\gamma}$=band or J-band was decreased. The orders of ${\alpha}$-band increasing power were $Cl^-$>$ClO{_4}{^-}$>$SO{_4}{^{2-}}$>$NO{_3}{^-}$ and 2-propanol>ethanol>methanol>ethylene glycol.