• 대한화학회지
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• 제33권6호
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• pp.601-606
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• 1989

Amberite IR 120+양이온 교환수지를 사용하고, 용리액으로 EDTA 용액을 사용하였을 때, 란탄계열원소들($Pr^{3+},\;Nd^{3+},\;Sm^{3+},\;Er^{3+}$)의 분배비와 분리인자에 미치는 온도의 영향과 수지상의 보유이온의 종류에 따르는 영향을 연구하였다. 보유이온들에 있어서는, ${NH_4}^+,\;Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+},\;Zn^{2+}$ 및 $Ce^{3+}$들 중, $Ce^{3+}$이 Nd/Pr의 분리인자를 개선하는데 가장 좋은 효과를 주었으며, $Zn^{2+}$이 Sm/Nd와 Er/Sm이 분리인자를 개선하는데 가장 적당한 보유이온임을 규명하였다. 용리시킬 때 온도의 영향은, 보유이온에 따라 매우 다양하였으며, 온도를 상승시킬 때 분배비는 감소하였다. 그러나 분리인자는 항상 증가하지 않았으며 보유이온이$Ce^{3+}$일 때 온도를 상승시켜 보니, Nd/Pr, Sm/Nd의 분리인자가 증가하였고, 보유이온이 $Zn^{2+}$일 때 온도를 상승시켜 보니 Er/Sm의 분리인자가 증가함을 확인하였다.

• The Korean Journal of Physiology
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• 제16권1호
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• pp.69-76
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• 1982

The effect of parathyroid hormone on calcium and phosphate metabolism have been widely investigated, however less attention has been paid to the effect on urinary excretion. This study was performed for the purpose determining urinary excretion of Na, K, Ca, and $Po_4$, of 18 thyroparathyroidectomized (TPTX) rabbits, which were TPTX previously 7 to 10 days compared with the same normal ones. After TPTX 0.2 mg/day of synthyroid was donated to the rabbits. The concentration of electrolytes in the serum and urine was determined by the following method; Na and K were determined by means of flame photometry, Ca was by EDTA titration $method^{19)}$, and $Po_4$ by Fiske and Subba-Raw $method^{20)}$. The results as follows. The concentrations of electrolytes in the serum were 1) In the normal control rabbits (N = 25) (data, $Mean{\pm}S.E.$) $Na\;131.72{\pm}1.33\;mEq/L$, $K\;3.59{\pm}0.28\;mEq/L$, $Ca\;12.58{\pm}0.29\;mg%$, $Po_4\;4.50{\pm}\;0.45mg%$. 2) In the TPTX rabbits(N= 18) $Na\;140.6l{\pm}2.56\;mEq/L$, $K\;3.38{\pm}0.36\;mEq/L$, $Ca\;l2.18{\pm}0.45\;mg%$, $Po_4\;3.92{\pm}\;0.35\;mg%$. There was no significant change between the normal and TPTX rabbits. The concentration of elelctrolytes in the urine were variously changed. 3) In the normal rabbits. $Na\;8.40{\pm}1.09\;mEq/L$, $K\;81.59{\pm}10.19\;mEq/L$, $Ca\;16.02{\pm}3.12\;mg%$, $Po_4\;13.16{\pm}2.89mg%$. 4) In the TPTX rabbits, $Na\;14.57{\pm}3.39\;mEq/L$ slight ncreased, $K\;116.06{\pm}12.77\;mEq/L$ significant increased (P<0.05), $Ca\;18.90{\pm}5.44\;mg%$ no significant increased, $Po_4\;43.38{\pm}8.67\;mg%$ significant increased (p<0.01). The effect of TPTX was assumed that it affected upon increasing tubular secretion of $K^+$ and inhibition of the tubular reabsorption of $Po_4$.

• 한국식품영양과학회지
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• 제18권3호
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• pp.348-355
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• 1989

Alkaline protease 생성능이 강한 Aspergillus fumigatus 균주를 토양에서 분리하고, 생성효소를 정제하여 특성을 조사한 결과 최적 pH는 9.0, pH안정성은 $pH\;8.0{\sim}10.0$, 최적온도는 $50^{\circ}C$였으며, $50^{\circ}C$이하의 온도에서 안정하나 그 이상의 온도에서는 급격한 효소 불활성화를 보였고, 금속염 $Mn^{++},\;Cu^{++},\;Ba^{++},\;Mg^{++}$ 등에 의해서 활성이 다소 증대되나 $K^+,\;Fe^{+++},\;Ag^{++},\;Pb^{++},\;Na^+,\;Ca^{++},\;Hg^+,\;Zn^{++}$에 의해 저해를 받았다. 활성저해제인 EDTA, 2,4-DNP, ${\varepsilon}-amino$ caproic acid에는 큰 저해를 받지 않으나, PCMB에 많은 저해를 받는 것으로 미루어 활성 부위가 SH기인 cystein protease로 추정되었다. Km값은 $8.33{\times}10^{-4}mole/{\ell}$, Vmax는 $47.62{\mu}g/min$였으며, casein과 hemoglobin을 trypsin보다 더 잘 분해하고, casein을 hemoglobin보다 잘 분해하였다.

• 한국토양비료학회지
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• 제50권6호
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• pp.497-508
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• 2017

This study aimed to investigate correlations between concentrations of extractable Arsenic (As) with varying chemical solutions (0.1 M $Ca(NO_3)_2$, 0.1 M $(NH_4)2HPO_4$, 0.5 M EDTA, Mehlich 3, and 0.5 M $NaHCO_3$) and those of As in crops, and then to seek the most suitable soil extraction method for predicting the potential of As uptake in crops cultivated in soils contaminated with As. For a mesocosm experiment, pepper (Capsicum annuum L.), soybean (Glycine max L.), and rice (Oryza sativa L.) were cultivated for three months in pots containing soils taken from the arable areas near abandoned mines in Korea. Following the cultivation, soil pH and DOC significantly increased by treatments of lime and lime plus compost, respectively, while insignificant influences in changing total and all extractable As concentrations were found in all soils. Arsenic concentration in edible part of all crops considerably depended on the extractable As concentration in the soils, particularly with Mehlich 3. All extractable As concentrations in the soils of C. annuum and G. max were significantly correlated with As concentration in their edible parts. For O. sativa, the extractable concentrations of Mehlich 3 ($R^2$: 0.18 at p: 0.006) and EDTA ($R^2$: 0.11 at p: 0.036) showed only marked relationships with As concentration in the edible part. These results may indicate that the Mehlich 3 and EDTA are soil extractants to determine phytoavailable As in soil that provide better prediction for As transfer from soil to crop.

• 한국의류학회지
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• 제7권2호
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• pp.19-25
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• 1983

The purpose of this study was to investigate the effects of laundry variables and additives on the removal of deposited calcium on the cotton fabric. Samples of calcium deposited fabric was made by treating fabric with $CaC1_2$ and $Na_2CO_3$ solution subsequently. The experimental variables were: 1) NaOH concentration ($0.0001\%$, $0.0005\%$, $0.001\%$, $0.005\%$, $0.01\%$) 2) Alkaline builders(sodium carbonate, sodium meta silicate) 3) Sequestering agents(STPP and EDTA concentration: $0.02\%$, $0.04\%$, $0.06\%$, $0.08\%$, $0.1\%$, $0.15\%$, $0.2\%$) 4) Temperatures($25\pm1^{\circ}C$, $40\pm1^{\circ}C$, $60\pm1^{\circ}C$) 5) Edge-abrasion to the removal of deposited calcium on the cotton fabric. The fabric was washed for 15 minutes in a washing machine(Model: Gold Star WP-3007) or Launder-0-meter(40$\~$45 r.p.m., Toyo Rika Instrument Inc.) and rinsed 3 times per every rinsing time. The amount of calcium deposits on the fabrics was determined by EDTA-back titration methods and edge-abrasion was evaluated by ASTM D 3886 method. The results of this study were as follows: 1) pH of surfactant solution(NaOH concentration) did not influence on the removal of deposited calcium on the cotton fabric. 2) Added alkaline builders did not influence on the removal of deposited calcium on the cotton fabric. 3) It was shown that STPP and EDTA were effective to remove deposited calcium. The removal of deposited calcium on the cotton fabric was proportionally increased with increasing concentration of STPP and EDTA. At high concentration, however, the rate was rather decreased with increasing concentration. 4) The temperature of washing solution did not influence on the removal of dedosited calcium on the cotton fabric. 5) As the removal of deposited calcium on the cotton fabric was increased, the rate of edge-abrasion of the fabric was gradually increased.

• 한국균학회지
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• 제33권2호
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• pp.75-80
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• 2005

섬유소분해능이 우수한 L. roseoalbus로부터 분리 정제한 CMCase의 활용에 대한 기초적인 자료를 제공하고자 실험하여 L. roseoalbus의 배양액으로부터 4단계를 거쳐 분자량이 28.5 kDa인 CMCase를 분리 정제하였다. 이 효소는 pH 4.0에서 최적의 활성을 보여주는 acidic CMCase로 $30^{\circ}C$에서 최대 활성을 나타냈다. EDTA에 의해 활성이 저해되는 것으로 보아 metalloenzyme으로 추정되며, PMSF에 의해 저해되는 것으로 보아 serine 잔기를 갖고 있는 효소로 판단된다. $Al_{2}(SO_{4})_{3}$와 $FeSO_{4}$에서는 효소활성이 높았으나 $CaCl_{2}$와 $Na_{2}MoO_{4}$에서는 효소 활성이 낮았다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권1호
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• pp.54-64
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• 2021

The chemical warfare agents (CWAs) have been developed for offensive or defensive purposes and used as chemical weapons in war and terrorism. The CWAs are exposed to the natural environment, transported through the water system and then eventually contaminate soil and groundwater. Therefore, effective decontamination technology to remediate CWAs are needed. The CWAs are extremely dangerous and prodution is strictly prohibited, therefore, it is difficult to use CWAs even in experimental purpose. In this study, 2,4-dichlorophenoxyacetic acid (2,4-D) was chosen as a model representative CWA because it is a simulant of anti-plant CWAs and one of the major component of agent orange. The optimum degradation conditions such as oxidant:activator ratio were determined. The effects of hydroxylamine and chelating agents such as citric acid (CA), oxalic acid (OA), malic acid (MA), and EDTA addition to increase Fe2+ activation were also investigated. Scavenger experiments using tert-butyl alcohol (TBA) and ethanol confirmed that although both sulfate (SO4•-) and hydroxyl radical (•OH) existed in Fe2+-persulfate system, sulfate radical was the predominant radical. To promote the Fe2+ activator effect, the effect of hydroxylamine as a reducing agent was investigated. In chelating agents assisted Fe2+-persulfate oxidation, the addition of 2 mM of CA and MA enhanced 2,4-D degradation. In contrast, EDTA and OA inhibited the 2,4-D removal due to steric hindrance effect.

• 미생물학회지
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• 제35권3호
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• pp.231-236
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• 1999

Penicillium oxalicum 으로부터 세포외로 분비되는 Anabaena cylindrica 분해효소의 분자량은 renaturation SDS-PAGE에서 약 22kDa 으로 확인되었으며, 분해 효소의 농축은 ultrafiltration cut off fraction 중 30-10 kDa 구간에서 수획하였다. 최적 활성조건의 측정 결과 적정 pH는 3.5-4.0, 적정반응 온도는 $20^{\circ}C$, 그리고 온도 안정성은 $4^{\circ}C$ 이하에서 100% 이상, 20-$90^{\circ}C$ 범위에서는 50% 이상의 활성을 나타내었다. 금속이온 및 효소안정제의 영향에서는 $Na^+$,$K^+$, $Ba^(2+)$, $Mg^(2+)$, $Mn^(2+)$의 양이온과 BSA는 효소의 활성을 촉진시키는 반면, $Ca^(2+)$, $Cu^(2+)$의 양이온과 EDTA, PMSF 는 효소의 활성을 억제하는 작용을 하였다. 이러한 금속이온과 안정제의 영향에서 1가, 2가 양이온에 의해 활성이 증가하고, $Fe^(3+)$, $Ca^(2+)$, $Cu^(2+)$의 양이온에 의해서는 활성이 감소하는 결과는 대부분의 세포벽 분해효소가 갖는 특성과 유사한 결과였다. 분해효소는 A. cylindrica 과 Micrococcus. luteus 의 세포벽을 기질로 사용한 효소의 활성 반응에서 반응 시작 후 1시간에서 5시간 사이에 반응 산물로 환원당의 양이 급격히 증가하였다.

• 한국응용곤충학회지
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• 제28권2호
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• pp.69-75
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• 1989

B. thuringiensis subsp. kurstaki HD-1을 아밀라제 생산배지에 $32^{\circ}C$로 24시간 배양하였을 때 아밀라제 활성은 0.40 units/ml 였고, 50mM EDTA에 의하여 활성이 억제되었으며, 기본배지에 soluble starch와 $Ca^{2+}$, $Mg^{2+}$, $Mn^{2+}$을 첨가했을 때 활성이 비교적 높았고, pH6.5와 7.0 사이에서, 온도 $55^{\circ}C$에서 비교적 활성이 높았다. 아밀라제 생산을 위한 최적 배지로는 0.2% soluble starch, 1.0% bacto-peptone, 0.3% beef extract, 0.5% NaCl, 0.3% $K_{2-}$$KH_{2}PO_{4}$, 0.012% CaCl.$2H_{2}O$, 0.005% $MnSO_{4}$.$H_{2}O$, 0.03% $MgSO_{4}$.$7H_{2}O$이었다. 효소 용액을 에 $HPO_{4}$, 0.1% 탄올 침전시켜 5ml의 0.1M 인산염 완충액에 용해한 용액의 비활성은 2.01 units/mg였고, starch에 대한 효소의 Km 값은 0.80 mg/ml였다.

• The Korean Journal of Physiology and Pharmacology
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• 제8권5호
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• pp.259-264
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• 2004

Cytolysin produced by Vibrio vulnificus has been incriminated as one of the important virulence determinants in V. vulnificus infection. Ion selectivity of cytolysin-induced pores was examined in a CPAE cell, a cell line of pulmonary endothelial cell, using inside-out patch clamp techniques. In symmetrical NaCl concentration (140 mM), intracellular or extracellular application of cytolysin formed ion-permeable pores with a single channel conductance of $37.5{\pm}4.0$ pS. The pore currents were consistently maintained after washout of cytolysin. Replacement of $Na^+$ in bath solution with monovalent ions $(K^+,\;Cs^+\;or\;TEA^+)$ or with divalent ions $(Mg^{2+},\;Ca^{2+})$ did not affect the pore currents. When the NaCl concentration in bath solution was lowered from 140 to 60 and 20 mM, the reversal potential shifted from 0 to -11.8 and -28.2 mV, respectively. The relative permeability of the cytolysin pores to anions measured at $-40\;mV\;was\;Cl^-\;=\;NO_2^-\;{\geq}\;Br^-\;=\;I^-\;> \;SCN^-\;>\;acetate^-\;>\;isethionate^-\;>\;ascorbic acid^-\;>\;EDTA^{2-},$ in descending order. The cytolysin-induced pore current was blocked by $CI^-$ channel blockers or nucleotides. These results indicate that V. vulnificus cytolysin forms anion-selective pores in CPAE cells.