• Food Science and Preservation
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• v.17 no.3
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• pp.430-434
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• 2010

This study was carried out to compare anti-oxidant activities of chaff vinegar liquors. We examined the effects of several kinds of chaff vinegar liquor (CA; CA1, chaff vinegar liquor; CA2, wood vinegar liquor; CA3, chaff vinegar liquor with red ginseng; and CA4, chaff vinegar liquor with rosemary) by 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing activity of plasma (FRAP) assay, and $Cu^{2+}$ reduction. The results showed that CA have potential in reducing DPPH, FRAP and $Cu^{2+}$ activity. CA was increased its anti-oxidant activity by the fermentation of rosemary extract. The present results suggest that the chaff vinegar liquor could be used for anti-oxidant agents and/or be developed for anti-oxidative potentiation of prototypes.

• Journal of Plant Biology
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• v.30 no.4
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• pp.249-255
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• 1987

The effect of polyamine and Ca2+ on D-glucose-6-phosphate cyclohydrolase activity was studied in Daucus carota root. The enzyme activity was reduced in response to increase in concentration of Ca2+, not the Ca2+-calmodulin complex. The inhibition effect due to Ca2+ was reversed by polyamine, especially remarkable at low concentration of Ca2+. The effect of the Ca2+ on the enzyme seemed to compete with polyamine according to the Lineweaver-Burk plot. The enzyme activity from carrot root protoplast cultured in the prescence of verapamil was higher than that of the control. Such cumulative results suggest that the inhibition by the Ca2+ and enhancement or reversal by polyamine could regulate the biosynthesis of pectin and hemicellulose to some extent.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.414-421
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• 1995

In order to establish informations important to the measurement of lipoxygenase (LOX) activity, providing conditions most favorable for its action and determining factors that inhibit activity, the influence of extraction buffer, substrate, pH, storage, temperature, NaCl, $CaCl_2$, other cations and antioxidants on LOX activity, and localization of LOX in cucumber tissues were carried out. The most favored substrate for LOX was linolenic acid followed by linoleic and arachidonic acids. LOX activity in both peel and mesocarp tissue extracts was maximum at pH 5.5 and relatively stable at $40^{\circ}C\;and\;50^{\circ}C$ temperature. The condition of 0.2 M NaCl with pH 5.0 was observed to provide optimum LOX stability. The enzyme activity was reduced by addition of cations, $Mn^{2+},\;Cu^{2+}\;or\; Al^{3+}$, except $Ca^{2+}$ which stimulated activity of LOX. Butylated hydroxy anisole (BHA) and propyl gallate decreased LOX activity with increasing concentration. Cucumber peel had higher activity than other tissues, locule or mesocarp, of cucumber.

• The Korean Journal of Zoology
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• v.28 no.1
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• pp.31-43
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• 1985

The $(Ca^{2+}+Mg^{2+})$-ATPase has been purified homogeneously from sarcoplasmic reticulum of rat skeletal muscle by sucrose density gradient centrifugation. The purified enzyme has a molecular weight of 115,000 as judged by polyacrylamide gel electrophoresis in the presence of sodium dedecyl sulfate, and therefore has the same size of the enzyme in rabbit and chick skeletal muscle. $Ca^{2+}, Mg^{2+}, Fe^{2+}, Co^{2+}, and Mn^{2+}$ at 50 $\\muM$ show stimulatory effect on the ATP-ase, while $Zn^{2+}, Cu^{2+}, and Hg^{2+}$ inhibit it at the same concentration. The ATPase activity is insensitive to antimalarial drugs such as quinine and quinacrine, but is sensitive to inhibition by p-hydroxymecurie benzoate and phenylmethylsulfonylfluoride. The enzyme has optimum pH of 6 to 7 and Km value for ATP is estimated to be 98 $\\muM$. Thus, a number of biochemical properties of this enzyme appear to be different from those of the enzyme that have been isolated from rabbit skeletal muscle. The $(Ca^{2+}+Mg^{2+})$-ATPase appears to be selectively degraded in microsomal fraction. The activity of metalloendoprotease is evident in the microsomal preparation when assayed by radioactively labeled protein substrate, such as $^{3}H-casein and $^{125}I$-insulin. However, it is presently unclear whether the metalloendoprotease is responsible for the degradation of the $(Ca^{2+}+Mg^{2+})$-ATPase.

• Progress in Medical Physics
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• v.15 no.4
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• pp.220-227
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• 2004

In N-type $Ca^{2＋}$ channels, the mechanism of inactivation - decline of inward current during a depolarizing voltage step- is still controversial between voltage-dependent inactivation and $Ca^{2＋}$ -dependent inactivation. In the previous paper we demonstrated that fast component of inactivation of N-type calcium channels does not involve classic $Ca^{2＋}$ -dependent mechanism and the slowly inactivating component could result from a $Ca^{2＋}$ -dependent process. However, there should be signal transduction pathway which enhances inactivation no matter what the inactivation mechanism is. We have investigated the effect of phosphorylation on calcium channels of rat sympathetic neurons. Intracellular dialysis with the phosphatase inhibitors okadaic acid markedly enhanced the inactivation. The rapidly inactivating component is N-type calcium current, which is blocked by $\omega$-conotoxin GVIA. Staurosporine, a nonselective protein kinase inhibitor, prevented the action of okadaic acid, suggesting that protein phosphorylation is involved. More specifically lavendustin C, inhibitor of CaM kinase II, prevented the action of okadaic acid, suggesting that calmodulin dependent pathway is involved in inactivation process. It is not certain to this point whether phosphorylation process is inactivation itself. Molecular biological research regarding binding site should be followed to address the question of how the divalent cation binding site is related to phoshorylation process.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.621-626
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• 1992

The effects of $Ca^{2+}$ ion on the charge transfer(CT) interaction of $4-(C_9H_{19})C_6H_4O(CH_2CH_2O)_{40} [NP-(EO)_{40}]$ with iodine in aqueous solution were investigated by UV-visible spectrophotometer. Maximum absorption wavelengths to the CT interaction were in the vicinity of 390 nm, and by the addition of $Ca^{2+}$ ion shifted toward 370 nm. Above CMC, the intensity of the CT interaction by the addition of $Ca^{2+}$ ion were increased and then decreased. The increase in the intensity of CT band were attributed to the increase of the donor-acceptor overlap with iodine caused by the compactness of micelle in the presence of $Ca^{2+}$ ion. These phenomena suggest that the linear oxyethylene(EO) chains, relatively free to assume various configuration in aqueous solution, could form a pseudo-crown ether structures capable of forming complexes with $Ca^{2+}$ ion.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.735-742
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• 2012

This study tried to find a suitable method for enhancing the foam stability of cationic surfactants that normally generate less foam or no foam. Several trials were made to enhance the foam stability: addition of anionic surfactant, colloids and polymer. Cationic starch (CA-ST) did not form foam at all, while the foam stability of two other cationic surfactant also showed low levels; methyl triethanol ammonium methyl sulfate distearyl ester (CEQ90) for 46 sec. and Cetyl trimethyl ammonium chloride (CM29) for 31 seconds. Foam stability of cationic surfactants were significantly affected by addition of anionic surfactant, sodium dodecyl sulfate (SDS). Foam stability of CA-ST was significantly enhanced by addition of SDS, while those of CEQ90 and CM29 were decreased. Addition of colloids ($SiO_2$, kaolin) and polyvinyl alcohol (PVA) enhanced foam stabilities of CEQ90 and CM29. However, CA-ST did not form foam even in the presence of colloids or PVA. Effect of simultaneous addition of colloids and anionic surfactant on foam stability of cationic surfactant showed that foam stability of cationic surfactant was more influenced by addition of anionic surfactant than colloids. Effect of simultaneous addition of PVA and anionic surfactant on the foam stability of cationic surfactant also showed that presence of anionic surfactant significantly affect the foam stability of cationic surfactant. Foam stability of CA-ST was greatly increased to 8,780 seconds by addition of SDS 0.14% and PVA 2.5%. The foam stability of CA-ST was 8 times higher than CEQ 90. This study suggested that cationic surfactants not forming foam can generate foam by addition of anionic surfactant and its stability can be additionally increased by addition of colloids and PVA. The study results showed that enhancement in foam stability of cationic surfactant was prominently affected by the concentration of anionic surfactant added.

• KSBB Journal
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• v.19 no.2
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• pp.159-163
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• 2004

The X-ray structure of the cydodextrin-glucanotransferase of Bacillus macerans was solved by molecular replacement at 2.0 ${\AA}$ resolution. The refined structure has a crystallographic R-factor of 16.6%, (R$\sub$free/ = 20.5%). A new metal binding site occupied by two Ca$\^$2+/-ions was found at an accession channel of the active site. There is a large accumulation of negative charges that bind these Ca$\^$2+/-ions, thereby connecting segment ${\beta}$13-${\alpha}$G (residue 254-276) to the main body of domain A (at ${\alpha}$H, residue 283-297). The segment 313-${\alpha}$G contains the catalytic residue Glu258 between subsite 1 and -1 and Tyr260 (subsite 2) which is located at the entrance of the active site. The Ca$\^$2＋/-site 3a,b may have a major role for the activity and specificity of this CGTase, although it is not even conserved for the a-subclass of CGTases.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.535-540
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• 1996

Potato slices were dipped in solution of 2% CaCl$_2$, and 1% chitosan or preheated in each of these solutions for refrigeration for 4 weeks at 5$^{\circ}C$. Changes in L value, content of total phenol and chlorogenic acid and po lyphenol oxidase activity were determined. During refrigeration, it was found that L values of potato slices treated with CaCl$_2$, (CaPS) and those treated with chitosan (ChPS) increased. Contents of total phenol and chlorogenic acid of potato slices decreased, While potato slices preheated in CaCl, solution (Hcaps) showed much decreases. And polyphenol oxidase (PPO) activity of potato slices decreased except CaPS and decreases in PPO activities were much larger in preheated potato slices. From these results, of those treatments used, chitosan treatment combined with preheating have shown to be effective to control enzymatic browning of potato slices during refrigeration.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.166-166
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• 2013

최근에 희토류 이온이 도핑된 형광체를 발광 소자, 레이저, 섬광재료, 광섬유, 촉매, 디스플레이와 같은 다양한 분야에 응용하기 위한 연구에 상당한 관심이 집중되고 있으며, 희토류 이온이 도핑된 발광 물질은 음극선관, 램프 조명, 플라즈마 디스플레이, X선 검출기, 전계 방출 디스플레이 소자를 포함한 다양한 영역에 응용되고 있다. 본 연구에서는 고상 반응법을 사용하여 발광 효율이 높은 적색과 주황색 형광체를 제조하고자 서로 다른 활성체 이온 Eu3+, Sm3+의 농도를 변화 시키면서 두 종류 Ca1-1.5xTa2O6:Eux3+와 Ca1-1.5xTa2 O6:Smx3+ 형광체 분말을 합성하였다. 특히, 활성제 이온의 농도비에 따른 형광체 분말의 결정 구조, 표면 형상, 입자의 크기, 흡광과 발광 특성을 측정하였다. 그림은 활성체 이온의 함량비를 달리하여 합성한 Ca1-1.5xTa2O6:Eux3+, Ca1-1.5xTa2O6:Smx3+ 형광체 분말에서 측정한 흡광(photoluminescence excition) 스펙트럼의 결과를 나타낸 것이다. 여기 파장 399 nm로 여기 시킨 Ca1-1.5xTa2O6:Eux3+ 형광체 분말의 경우에, 발광 세기가 가장 강한 617 nm의 주 피크가 관측되었다. 또한, 여기 파장 410 nm로 여기 시킨 Ca1-1.5xTa2O6:Smx3+ 형광체 분말의 경우에는 발광 세기가 가장 강한 주 피크는 609 nm에서 나타났다. 실험 결과로부터, Eu3+와 Sm3+ 이온이 각각 도핑된 CaTa2O6 형광체의 경우에는 색 순도가 높은 파장과 발광 세기는 Eu3+ 이온인 경우에 0.15 mol, Sm3+ 이온이 도핑되는 경우에는 0.05 mol이 최적의 합성 조건임을 알 수 있었다.