• Toxicological Research
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• 제35권2호
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• pp.161-165
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• 2019

Cysteamine has been used in cosmetics as an antioxidant, a hair straightening agent, and a hair waving agent. However, recent studies indicate that cysteamine can act as an allergen to hairdressers. The objective of this study was to develop and validate a simple and effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the measurement of cysteamine and its dimer, cystamine. Sodium 1-heptanesulfonate (NaHpSO) was used as an ion-pairing agent to improve chromatographic performance. Separation was performed on a Gemini C18 column ($250mm{\times}4.6mm$, $5{\mu}m$ particle size) using a mobile phase composed of 85:15 (v/v) 4 mM NaHpSO in 0.1% phosphoric acid:acetonitrile. UV absorbance was monitored at 215 nm. The RP-HPLC method developed in this study was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, and recovery. Cysteamine and cystamine were chromatographically resolved from other reducing agents such as thioglycolic acid and cysteine. Extraction using water and chloroform resulted in the recovery for cysteamine and cystamine ranging from 100.2-102.7% and 90.6-98.7%, respectively. This validated RP-HPLC method would be useful for quality control and monitoring of cysteamine and cystamine in cosmetics.

• 한국식품영양과학회지
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• 제9권1호
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• pp.59-73
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• 1980

A detailed procedure was described for the isolation of cratine kinase (ATP-Creatine phosphotransferase, E. C. 2. 7. 3. 2.) from the muscle of the snake Bungarus fasciatus. The original isolation procedure of Kuby et al. for the rabbit muscle enzyme has been modified and extended to include a chromatographic step. The properties of the enzyme have been investigated and kinetic constants for the reverse reactions determined as the followings: 1) A molecular weight of the enzyme was determined by gel filteration on Sephadex G-100 and by electrophoresis on SDS-polyacrylamide was 86,000. 2) Two reactive sulphydryl groups were detected with dithiobis nitrobenzoic acid (DTNB). 3) The nucleotide substrate specificity in the reverse reaction was determined as ADP*2'-dADP＞GDP＞XDP＞UDP with magnesium as the activating metal ion. 4) The order of the metal specificity in the reverse reaction Mg>Mn>$Ca{\sim}Co$ was determined with ADP as substrate. 5) A detailed kinetic analysis was carried out in the reverse direction with $MaADP^-$ as the nucleotide substrate. Initial velocity and product inhibition studies($MaADP^{2-}$ competitive with respect to MgADP- and noncompetitive with respect to $N-phosphorycreatine^{2-}$ ; Creatine competitive with respect to $N-phosphorycreatine^{2-}$ and noncompetitive with respect to Ma $ADP^-)$ indicated that the reaction obeyed a sequential mechanism of the rapid equilibrium random type.

• Applied Biological Chemistry
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• 제36권6호
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• pp.539-546
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• 1993

본 연구에서는 Cheddar 치즈의 숙성기간을 단축시키고 flavor를 증진시키기 위하여 Micrococcus sp. LL3를 치즈 제조시에 첨가할 목적으로 본 균주가 생성하는 aminopeptidase의 특성을 조사하였으며, 또한 본 효소를 정제하였다. L-Leucine-p-nitroanilide를 기질로 사용 하였을 때 본 효소의 최적온도와 pH는 각각 $30^{\circ}C$ 및 7.0이었다. 본 효소는 $50^{\circ}C$까지의 온도에서 10분간 방치하였을 경우에도 안정하였다. $Mg^{++}$ ion에 의해 본 효소의 활성이 촉진되었으나 $Hg^{++}$ ion과 EDTA나 1,10-phenanthroline에 의해서 효소활성이 거의 실활되어 metallopeptidase인 것으로 추정되었다. 본 효소의 기실 특이성은 광범위 하였으나, N-terminal amino acid로서 arginine을 함유한 peptide는 분해하지 못했다. 본 균주가 생성하는 aminopeptidase의 정제를 위하여 DEAE-Sephacel ion chromatography및 gel filtration을 실시하였으며, 이때 분자량 46,500의 효소를 얻을 수 있었다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2003년도 제2차 연례학술대회 발표논문집
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• pp.5-5
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• 2003

The purple acid phosphatases comprise a family of binuclear metal-containing enzymes. The metal centre contains one ferric ion and one divalent metal ion. Spectroscopic studies of the monomeric, ${\sim}$36 kDa mammalian purple acid phosphatases reveal the presence of an Fe(III)Fe(II) centre in which the metals are weakly antiferromagnetically coupled, whereas the dimeric, ${\sim}$110 000 kDa plant enzymes contain either Fe(III)Zn(II) or Fe(III)Mn(II). The three dimensional structures of the red kidney bean and pig enzymes show very similar arrangements of the metal ligands but some significant differences beyond the immediate vicinity of the metals. In addition to the catalytic domain, the plant enzyme contains a second domain of unknown function. A search of sequence databases was undertaken using a sequence pattern which includes the conserved metal-binding residues in the plant and animal enzymes. The search revealed the presence in plants of a 'mammalian-type' low molecular weight purple acid phosphatase, a high molecular weight form in some fungi, and a homologue in some bacteria. The catalytic mechanism of the enzyme has been investigated with a view to understanding the marked difference in specificity between the Fe-Mn sweet potato enzyme, which exhibits highly efficient catalysis towards both activated and unactivated phosphate esters, and other PAPs, which hydrolyse only activated esters. Comparison of the active site structures of the enzymes reveal some interesting differences between them which may account for the difference. The implications fur understanding the physiological functions of the enzymes will be discussed.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.270-276
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• 1998

Extracellular ${\alpha}$-glucosidase was purified to homogeneity from moderately thermophilic Bacillus sp. DG0303. The thermostable ${\alpha}$-glucosidase was purified by ammonium sulfate fractionation, ion-exchange chromatography, preparative polyacrylamide gel electrophoresis (PAGE), and electroelution. The molecular weight of the enzyme was estimated to be 60 kDa by SDS-PAGE. The optimum temperature for the action of the enzyme was at $60^{\circ}C$. It had a half-life of 35 min at $60^{\circ}C$. The enzyme was stable at the pH range of 4.5~7.0 and had an optimum pH at 5.0. The enzyme preparation did not require any metal ion for activity. The thermostable ${\alpha}$-glucosidase hydrolyzed the ${\alpha}$-1,6-linkages in isomaltose, isomaltotriose, and panose, and had little or no activity with maltooligosaccharides and other polysaccharides. The $K_m$ (mM) for p-nitrophenyl-${\alpha}$-D-glucopyranoside (pNPG), panose, isomaltose, and isomaltotriose were 4.6, 4.7, 40.8, and 3.7 and the $V_{max}$(${\mu}mol{\cdot}min^-1$$mg^-1$) for those substrates were 5629, 1669, 3410, and 1827, respectively. The N-terminal amino acid sequence of the enzyme was MERVWWKKAV. Based on its substrate specificity and catalytic properties, the enzyme has been assigned to be an oligo-1,6-glucosidase.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.18-22
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• 1993

Oligofructo당 생산에 이용될 수있는 endoinulinase 분석방법은 그 균주가 endo- 및 exoinulinase를 함께 내는 경우, 일반적인 환원당 분석법으로는 정량하기가 어려워진다. 이 실험에서는 endoinulinase만을 선택적으로 정량하기 위한 하나의 방법으로써 항체 분석법을 이용하였다. Aspergillus niger ATCC 16882 조효소액을 CM-DEAE ion exchange chromatography, pI 2.5-5에서 preparative isoelectric focusing, HPLC gel filtration을 통해 순수하게 endoinulinase에 대한 항체를 얻었다.DEAE-ion exchange 및 protein A에서 정제된 이항체는 immunoassay 한 결과, exoinulinase 가 아닌 endoinulinase와 만 특이하게 반응하였고, immuno affinity chromatography 결과들은 배양액 중의 다른 단백질과 반응하지 않음이 확인되었다. 이눌린을 유일한 탄소원으로 한 배지에서 자란 1200여개의 야생균주들로부터 배양 특성이 우수한 균주를 1차로 선별하고 이 균주들의 endoinulinase 함량을 rocket immunoassay를 통하여 조사하였다. 이 중 1개의 균주는 Novozyme의 ATCC 1688와 비교할만한 정도의 endoinulinase를 배양액 중에 분비함을 확임할 수 있었다.

• 대한본초학회지
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• 제22권4호
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• pp.21-28
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• 2007

Objectives : Kyenegum has been popularly used long as the digestive. The purpose of this study was to investigate the purification and characteristics of protease obtained from Kyenegum crude enzyme. Methods : Kyenegum protease was purified by precipitation with ammonium sulfate followed by SP-Spharose ion exchange chromatography. The molecular weight of Kyenegum protease was estimated by SDS-PAGE electrophoresis. Results : Kyenegum protease was 3,087 units/mg protein specific activity, 14.5 purification fold and 9.8 % recovery. The molecular weight of protease was estimated to be 18 kDa. The isoelectric point was pI 8.97 and values of Km and Vmax of its were 48 mg/mL and 2 units/min, respectively. Conclusion : The result suggests that the protease obtained from Kyenegum has excellent stability of temperature, acid and collagen substrate specificity.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 1997년도 춘계 제44회 유가공 심포지움
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• pp.23-34
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• 1997

Calcium-stimulated ATPase ($Ca^{2+}$-ATPase) which has optimal pH value at 7.0 was found in the membrane fraction of human milk, and its enzymatic properties were studied. The purified $Ca^{2+}$-ATPase required 0.45 mM Ca ion for maximal activity. Among the nucleosides, $Ca^{2+}$-ATPase showed a higher substrate specificity to ATP and UTP than to CTP and GTP. $Ca^{2+}$-ATPase had apparent Km value of 0.065, and V max of 7.63 mol ATP hydrolyzed/mg pro-tein per min, respectively. $Ca^{2+}$-ATPase was potently inhibited by lanthanide, vanadate, and p-chloromercuribenzoate, and inactivated by EDTA, and CDTA and EGTA, but were unaffected by N-ethylmaleimide, $NaN_3$, ouabain, or oligomycin, and was completely inactivated by heating at $60^{\circ}C$ for 10 min. This enzyme activity was concentrated in the membrane fraction of the cream and skim milk membrane, but not founded in bovine milk.

• BMB Reports
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• 제28권2호
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• pp.94-99
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• 1995

The properties of binding sites in the active site of $Zn^{2+}$-glycerophosphocholine cholinephosphodiesterase were examined using substrates and inhibitors of the enzyme. Phosphodiesterase hydrolyzed p-nitrophenylphosphocholine, p-aminophenylphosphocholine, and glycerophosphocholine, but did not hydrolyze either acylated glycerophosphocholine or bis (p-nitrophenyl)phosphate, suggesting a size limitation for interaction with a glyceryl moiety-binding subsite. The hydrolysis of p-nitrophenylphosphocholine was competitively inhibited by glycerophosphocholine and p-aminophenylphosphocholine, while glycerophosphoethanolamine was a weak inhibitor. The enzyme was also inhibited by choline, but not by ethanolamine. Thiocholine, a much more potent inhibitor than choline, was more inhibitory than cysteamine, suggesting a strict specificity of an anionic subsite adjacent to a $Zn^{2+}$ subsite. Of all oxyanions tested, the tellurite ion was found to strongly inhibit the enzyme by binding to a $Zn^{2+}$ subsite. The inhibitory role of tellurite was synergistically enhanced by tetraalkylammonium salts, but not by glycerol. Deactivation of the enzyme by diethylpyrocarbonate was partially protected by choline, but not by glycerophosphate. It is suggested that the active site of phosphodiesterase contains three binding subsites.

• Journal of Ginseng Research
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• 제37권1호
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• pp.117-123
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• 2013

Polyphenol oxidase (PPO) was purified from fresh ginseng roots using acetone precipitation, carboxymethyl (CM)-Sepharose chromatography, and phenyl-Sepharose chromatography. Two isoenzymes (PPO 1 and PPO 2) were separated using an ion-exchange column with CM-Sepharose. PPO 1 was purified up to 13.2-fold with a 22.6% yield. PPO 2 bound to CM-Sepharose, eluted with NaCl, and was purified up to 22.5-fold with a 17.4% yield. PPO 2 was further chromatographed on phenyl-Sepharose. The molecular weight of the purified PPO 2 from fresh ginseng was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was about 40 kDa. The optimum temperature and pH were $20^{\circ}C$ and 7.0, respectively, using catechol as a substrate. Pyrogallol showed the highest substrate specificity. The effect of a PPO inhibitor showed that its activity increased slightly in the presence of a low concentration of citric acid. High concentrations of acidic compounds and sulfite agents significantly inhibited purified ginseng PPO 2.