• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.269-273
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• 2002

The amlyolytic enzymes $({\alpha}-amlyase,\;{\beta}-amlyase,\;glucoamlyase)$ and protease activities were studied during Kimchi fermentation. The optimum pH of Kimchi was 4.1 within 2 days at $20^{\circ}C$. The optimum acidity calculated as lactic acid was 0.44% within 2 days at $20^{\circ}C$. On the first day of fermentation, ${\alpha}-amlyase$ activity was reduced from 0.49 unit/mg protein to 0.20 unit/mg protein but increased in the later stage of fermentation. In case of ${\beta}-amlyase,\;glucoamlyase$ and protease showed the highest activity of 505.73, 13.43 and 1.72 unit/mg protein at the 2nd day of fermentation at $20^{\circ}C$. In the sensory evaluation of Kimchi were estimated taste, color, texture and overall acceptability. Overall acceptability of kimchi showed the highest score value on the 2nd day of fermentation, respectively.

• KSBB Journal
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• v.6 no.2
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• pp.143-146
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• 1991

The liquifying $\alpha-amylase$ production from B. subtilis, A. oryzae and B. natto using wheat and rice bran as low cost culture medium was investigated. Among 3 strains, B. natto showed heights productivity of $\alpha-amylase$ in the outer wheat bran medium. And the optimum culture condition is pH 6.8 and $37^{\circ}C$ for the production of $\alpha-amylase$. The $\alpha-amylase$ activity of the crude enzyme and the purified enzyme are 256 unit/ml and 10,700 unit/ml, respectivitly. The $\alpha-amylase$ from B. natto cultrtured in outer wheat bran medium was purified into nearly a pure state(98.7%). And the molecular weight of the purified $\alpha-amylase$ was 34,000.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.465-470
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• 1997

The human cDNA clone UDPGTh2, encoding a liver UDP-glucuronosyltransferase (UDPGT), was isolated from a .gamma.gt 11 cDNA library by hybridization to mouse transferase cDNA clone, UDPGTm1. The two clones had 74% nlicleotide sequence identities in the coding region. UDPGTh2 encoded a 529 amino acid protein with an amino terminus membrane-insertion signal peptide and a carboxyl terminus membrane-spanning region. In order to establish substrate specificity, the clone was inserted into the pSVL vector (pUDPGTh2) and expressed in COS 1 cells. Sixty potential substrates were tested using cells transfected with pUDPGTh2. The order of relative substrate activity was as follows: 4-hydroxyestrone > estriol >2-hydroxyestriol > 4-hydroxyestradiol > $6{\alpha}$-hydroxyestradiol >$5{\alpha}$-androstane-$3{\alpha}$, $11{\beta}$, $17{\beta}$-triol=5${\beta}$-androstane-$3{\alpha}$ ${\beta}$, $17{\beta}$-triol. There were only trace amounts of gulcuronidation of 2-hydroxyestradiol and 2-hydroxyestrone, and in contrast to other cloned transferase, no gulcuronidation of either the primary estrogens and androgens (estrone, $17{\beta}$estradiol/testosterone, androsterone) or any of the exogenous substrates tested was detected. A lineweaver-Burk plot of the effect of 4-hydroxystrone concentration on the velocity of glucuronidation showed an apparent Km of $13{\mu}M$. The unique specificity of this transferase might play an important role in regulating the level and activity of these potent and active estrogen metabolites.

• Journal of Technologic Dentistry
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• v.20 no.1
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• pp.37-49
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• 1998

The specimens used were Ag-25 Pd-15 Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age- hardening characteristics of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing. X-ray diffraction and electron microscope observations, electrical resistance, ergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, i.e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the $L1_0$ type face-centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affected by the Cu concentration. In stage II, decomposition of the ${\alpha}$ solid solution to a PdCu ordered phase($L1_0$ type) and an Ag-rich ${\alpha}2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was conclued that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipetation procedure was ${\alpha}{\to}{\alpha}+{\alpha}_2+PdCu {\to}{\alpha}_1+{\alpha}_2+PdCu$ at Pd/Cu = 1.7 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.505-512
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• 2017

Toxoplasma gondii cathepsin C proteases (TgCPC1, 2, and 3) are important for the growth and survival of T. gondii. In the present study, B-cell and T-cell epitopes of TgCPC1 were predicted using DNAstar and the Immune Epitope Database. A TgCPC1 DNA vaccine was constructed, and its ability to induce protective immune responses against toxoplasmosis in BALB/c mice was evaluated in the presence or absence of the adjuvant ${\alpha}-GalCer$. As results, TgCPC1 DNA vaccine with or without adjuvant ${\alpha}-GalCer$ showed higher levels of IgG and IgG2a in the serum, as well as IL-2 and $IFN-{\gamma}$ in the spleen compared to controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). Upon challenge infection with tachyzoites of T. gondii (RH), $pCPC1/{\alpha}-GalCer$ immunized mice showed the longest survival among all the groups. Mice vaccinated with DNA vaccine without adjuvant (pCPC1) showed better protective immunity compared to other controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). These results indicate that a DNA vaccine encoding TgCPC1 is a potential vaccine candidate against toxoplasmosis.

• Journal of Magnetics
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• v.16 no.2
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• pp.173-176
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• 2011

Fe-Cr alloys with different Cr contents were prepared by an arc melting technique. The alloys were isochronally aged in the range from $400^{\circ}C$ to $900^{\circ}C$ with $50^{\circ}C$ steps with a holding time of 100 hours. The ageing produced embrittlement in the alloys due to either the formation of a Cr-rich ${\alpha}'$ phase or a $\sigma$ phase at high temperatures. Magnetic Hysteresis Loop (MHL) and Micro-Vickers hardness were measured at each step to correlate the magnetic and mechanical properties. Coercivity and hardness of the alloys were increased and remanence decreased up to 500-$550^{\circ}C$ due to formation of a Cr-rich ${\alpha}'$ phase. Beyond 500-$550^{\circ}C$ range, the coercivity and hardness decreased and remanence increased due to the coarsening or dissolution of the Cr-rich ${\alpha}'$ phase. In the Fe-48% Cr alloy, formation of the $\sigma$ phase at $700^{\circ}C$ reduced the maximum induction of the alloy significantly.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.143-149
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• 1992

A bacterial strain No. 2, which highly produced a-glucosidase, was isolated from Kimchi and identified to be a similar species of Pediococcus halophilus. This enzyme was purified by protamine sulfate, ammonium sulfate fractionation, ion exchange and gel filtration. The maximal a-glucosidase activity was observed at pH 6.0 and this enzyme was stable at pH 6.0~ 7.5. The optimum temperature of this enzyme activity was $37^{\circ}C$, but enzyme activity was gradually lost above $37^{\circ}C$. This enzyme was activated by 10 mM MgCh and inhibited by 10 mM mercaptoethanol. The kinetics of PNPG(p-Nitrophenyl-a-D-glucopyranoside) and maltose were Kp0.52 mM/27.5 pg protein, $V_{max}$= 0.021 mM/min 27.5 ${\mu}g$ protein and $K_m$= 0.32 mMD7.5 ${\mu}g$ protein, $V_{max}$= 0.025 mM/min 27.5 ${\mu}g$ protein, respectively. The molecular weight of $\alpha$-glucosidase was about 37, 000.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.221-228
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• 1987

The extracellular adenine deaminase from Nocardioides sp. J-275L was purified by the following techniques: ammonium sulfate fractionation, DEAE-Cellulose, DEAE-Sephadex A-50 column chromatography, and Sephacryl S-200 superfine gel filtration. The enzyme was partially purified about 3889.5-fold with about 5.2% yield by these procedures. The molecular weight of the enzyme was 39,000 by a calibrated Sephacryl S-200 superfine column chromatography. The enzyme was stable at pH 7.5 and up to $40^{\circ}C$. Glycerol was effective on the stabilization of the enzyme during storage. The optimum pH and temperature of the enzyme were around pH 7.5 and $40^{\circ}C$, respectively. The apparent Michaelis constant Km of the enzyme for adenine was $7.4\times 10^{-5}$M. The purine analogues, 6-chloropurine, 2,6-diaminopurine, 6-bromopurine, 4-aminopyrazolo [3.4-d]pyrimidine, and 8-azaadenine were substrates for the enzyme. 6-Dimethylaminopurine was a competitive inhibitor of the enzyme. The enzyme was inhibited by 1mM of $Cu^{2+}, Fe^{3+}, Pb^{2+}, Hg^{2+}$, and $Ag^{+}$, and 1mM of $\alpha$,$\alpha$'-dipyridyl, pentachlorophenol, and pCMB.

• Journal of the Korean Chemical Society
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• v.22 no.1
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• pp.30-36
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• 1978

The kinetics of hydrolysis of ${\alpha}$-nitrobenzaldehydephenylhydrazone derivatives (p-$NO_2$, m-$NO_2$, p-Cl, p-$CH_3$) have been investigated by UV spectrometry in 25% dioxane-water at $25^{\circ}C$ and a rate equation which can be applied over wide pH range was obtained. From the rate equation and the effect of solvent, substituent and pKa on the rate equation, the following reaction mechanisms were proposed. Below pH 3.0 the hydrolysis of ${\alpha}$-nitrobenzaldehydephenylhydrazone proceeds by $S_N1$ mechanism, while above pH 4.0 the hydrolysis proceeds through 1,3-dipole ion mechanism. In the range of pH from 3.0 to 4.0 these two reactions occur competitively.

• Journal of the Korean Magnetics Society
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• v.1 no.1
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• pp.25-29
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• 1991

It has been found that the as-quenched ribbons of $Sm_{x}Fe_{100-x-y}Ti_{y}(3.8{\leq}x{\leq}11.5,\;3.8{\leq}y{\leq}19.2)$ are composed of metastable $TbCu_{7}-type$ structure, ${\alpha}-(Fe,\;Ti),\;Fe_{2}Ti$ and an unknown phase accompanying strong diffraction line at $d=2.14{\AA}$. The metastable $TbCu_{7}-type$ phase, which was formed by rapid quenching, did not transform fully to the stable phases after annealing at $850^{\circ}C$ for 45 minutes except the one existed in $SmFe_{11}Ti$ melt-spun ribbon. The $SmFe_{11}Ti$ melt-spun ribbon, annealed at $850^{\circ}C$ for 45 minutes in vacuum, was found to be composed of $ThMn_{12}$. $\alpha$-(Fe, Ti) and $Fe_{2}Ti$ phases. The formation of $\alpha$-(Fe, Ti) and $Fe_{2}Ti$ phases in this melt-spun ribbon was due to the evaporation of Sm atoms during the high temperature annealing. The atomic ratios for the surface and the inside of $SmFe_{11}Ti$ melt-spun ribbon annealed in vacuum were $SmFe_{25.8}Ti_{2.6}$ and $SmFe_{11.7}Ti_{1.0}$ respectively. It is thought to be that much of $\alpha$-(Fe, Ti) and $Fe_{2}Ti$ phases exist on the surface of ribbon.