• Title/Summary/Keyword: metal specificity

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Korean Dress Collection Held in the Museum of Archaeology and Anthropology in Cambridge (캠브리지 대학 고고인류학 박물관 소장 한복유물에 관한 연구)

  • Kim, Soon-Young
    • Journal of the Korean Society of Costume
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    • v.61 no.9
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    • pp.84-96
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    • 2011
  • This paper investigates the formative features and the historical meaning of the Korean dress collection held in the Museum of Archaeology and Anthropology in Cambridge. The Museum holds a total of eleven items of koran dresses that were donated by two anthropologists in the first half of the twentieth century. Male dresses consist of a white cotton jacket (Jeogori), a under-vest (Deungbaeja) made of light wisteria rings, a headband (Manggeon) made of horsehair, a broad brimmed top hat (Gat) made of black horsehair gauze, an oilskin cover (Galmo) drawn over the hat in wet weather, and a hemispherical hat box (Gatjib). Female dresses comprise a pink silk jacket (Jeogori), a blue silk skirt (Chima) with pleats, a pair of woman's white cotton trousers (Sokgot), a black silk cap (Jobawi) decorated with pink tassels and imitation pearls, and a pair of green and magenta silk shoes (Danghye) with leather soles and metal rivets. Theses Korean dresses show what the western anthropologists had interests in. When collectors collect the folk objects, they thought much of the specificity of shape and material, the esthetic appreciation, and the representation of daily life. In terms of the value as the historical materials in the history of Korean dress, the under-vest of wisteria, the hat box, and the female dresses are worth paying attention to. The under-vest is one that was produced in earlier time among the remaining under-vests. The hat box represents that the hat belonged to the merchant classes. The female dress items show daily dresses worn by women of higher classes of the society in the 1920s.

Biochemical Properties of Eggplant Fruit Lectin. (가지 열매 lectin의 생화학적 성질)

  • Roh, Kwang-Soo
    • Journal of Life Science
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    • v.18 no.3
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    • pp.350-356
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    • 2008
  • Biochemical characterization including hemagglutination of erythrocytes, molecular weight, optimum temperature, thermal stability, optimum pH, carbohydrate specificity, and inhibitory effect of metal ion were studied in lectin of eggplant (Solanum melongena L.) fruit prepared by ammonium sulfate fractionation and affinity chromatography. This lectin was agglutinated by trypsin-treated rat blood erythrocyte. The molecular weight of this lectin by SDS-PAGE was estimated to be approximately 19.3 kDa of a single band. This lectin has no activity by 7 carbohydrates containing D-glucose. The optimum range of temperature and pH were $10-20^{\circ}C$ and pH 6.2-7.2, respectively. This lectin was relatively stable at $20-70^{\circ}C$. And the activity of this lectin was not inhibited by $Ca^{2+},\;Co^{2+},\;Cu^{2+},\;Fe^{2+},\;Mg^{2+}$, and $Mn^{2+}$.

Overexpression of aprE2, a Fibrinolytic Enzyme Gene from Bacillus subtilis CH3-5, in Escherichia coli and the Properties of AprE2

  • Jeong, Seon-Ju;Cho, Kye Man;Lee, Chang Kwon;Kim, Gyoung Min;Shin, Jung-Hye;Kim, Jong Sang;Kim, Jeong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.24 no.7
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    • pp.969-978
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    • 2014
  • The aprE2 gene with its prosequence from Bacillus subtilis CH3-5 was overexpressed in Escherichia coli BL21(DE3) by using plasmid pET26b(+). After IPTG induction, active and mature AprE2 was produced when cells were grown at $20^{\circ}C$, whereas inactive and insoluble enzyme was produced in a large amount when cells were grown at $37^{\circ}C$. The insoluble fraction was resuspended with 6 M guanidine-HCl and dialyzed against 2 M Tris-HCl (pH 7.0) or 0.5 M sodium acetate (pH 7.0) buffer. Then active AprE2 was regenerated and purified by a Ni-NTA column. Purified AprE2 from the soluble fraction had a specific activity of $1,069.4{\pm}42.4U/mg$ protein, higher than that from the renatured insoluble fraction. However, more active AprE2 was obtained by renaturation of the insoluble fraction. AprE2 was most stable at pH 7 and $40^{\circ}C$, respectively. The fibrinolytic activity of AprE2 was inhibited by PMSF, but not by EDTA and metal ions. AprE2 degraded $A{\alpha}$ and $B{\beta}$ chains of fibrinogen quickly, but not the ${\gamma}$-chain. AprE2 exhibited the highest specificity for N-succinyl-Ala-Ala-Pro-Phe-pNA. The $K_m$ and $k_{cat}/K_m$ of AprE2 was 0.56 mM and $3.10{\times}10^4S^{-1}M^{-1}$, respectively.

Structure and $Ca^{2+}$-ion effects on the function of $\alpha$-cyclodextrin Glucanotransferase from B. macerans : An X-ray study (Bacillus macerans에서 정제한 $\alpha$-cyclooextrin glucanotransferase의 구조와 칼슘이온이 기능에 미치는 영향 : X-ray 연구)

  • 최희욱;홍순강
    • 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.

In Vitro Determination of Dengue Virus Type 2 NS2B-NS3 Protease Activity with Fluorescent Peptide Substrates

  • Khumthong, Rabuesak;Angsuthanasombat, Chanan;Panyim, Sakol;Katzenmeier, Gerd
    • BMB Reports
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    • v.35 no.2
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    • pp.206-212
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    • 2002
  • The NS2B-NS3(pro) polyprotein segment from the dengue virus serotype 2 strain 16681 was purified from overexpressing E. coli by metal chelate affinity chromatography and gel filtration. Enzymatic activity of the refolded NS2B-NS3(pro) protease complex was determined in vitro with dansyl-labeled peptide substrates, based upon native dengue virus type 2 cleavage sites. The 12mer substrate peptides and the cleavage products could be separated by reversed-phase HPLC, and were identified by UV and fluorescence detection. All of the peptide substrates (representing the DEN polyprotein junction sequences at the NS2A/NS2B, NS2B/NS3, NS3/NS4A and NS4B/NS5 sites) were cleaved by the recombinant protease NS2B-NS3(pro). No cleavage was observed with an enzymatically inactive S135A mutant of the NS3 protein, or with a modified substrate peptide of the NS3/NS4A polyprotein site that contained a K2093A substitution. Enzymatic activity was dependent on the salt concentration. A 50% decrease of activity was observed in the presence of 0.1M sodium chloride. Our results show that the NS3 protease activity of the refolded NS2B-NS3(pro) protein can be assayed in vitro with high specificity by using cleavage-junction derived peptide substrates.

Purification and Substrate Specificity of Debaryomyces sp. ${\alpha}$-Galactosidase by Mannobiose-Sepharose Affinity Column Chromatograpy (Mannobiose-Sepharose 담체합성 및 Affinity column chromatograpy에 의한 Debaryomyces sp. 유래 ${\alpha}$-Galactosidase의 정제 및 기질 특이성)

  • Park, Gwi-Gun
    • Applied Biological Chemistry
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    • v.49 no.3
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    • pp.180-185
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    • 2006
  • ${\alpha}$-Galactosidase was partially purified from the culture filtrate of Debaryomyces sp. by Mannobiose-Sepharose affinity column chromatography. The galactosidase exhibited maximum activity at pH 4.0 and $60^{\circ}C$, and was stable in the pH and temperature ranges of 3 to 4.5 and 30 to $50^{\circ}C$, respectively. The enzyme was inhibited by $Hg^{2+}\;and\;Ag^{2+}$. The enzyme activity was not affected considerably by treatment with other metal compounds. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and $Gal^3Man_3$ ($6^3-{\alpha}$-galactosyl-1,4-mannotriose) to galactose and mannotriose. On the contrary, it could not hydrolyze $Gal^3Man_4$ ($6^3-{\alpha}$-galactosyl-1,4-mannotetraose).

A New Functional Model of Catechol Dioxygenases: Properties and Reactivity of [Fe(BLPA)DBC]$BPh_4$

  • Lim, Ji H.;Lee, Ho J.;이강봉;Jang, Ho G.
    • Bulletin of the Korean Chemical Society
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    • v.18 no.11
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    • pp.1166-1172
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    • 1997
  • [FeⅢ(BLPA)DBC]BPh4, a new functional model for the catechol dioxygenases, has been synthesized, where BLPA is bis((6-methyl-2-pyridyl)methyl)(2-pyridylmethyl)amine and DBC is 3,5-di-tert-butylcatecholate dianion. The BLPA complex has a structural feature that iron center has a six-coordinate geometry with N4O2 donor set. It exhibits EPR signals at g=5.5 and 8.0 which are typical values for the high-spin FeⅢ (S=5/2) complex with axial symmetry. The BLPA complex reacts with O2 within a few hours to afford intradiol cleavage (75%) and extradiol cleavage (15%) products which is very unique result of all [Fe(L)DBC] complexes studied. The iron-catecholate interaction of BLPA complex is significantly stronger, resulting in the enhanced covalency of the metal-catecholate bonds and low energy catecholate to FeⅢ charge transfer bands at 583 and 962 nm in CH3CN. The enhanced covalency is also reflected by the isotropic shifts exhibited by the DBC protons, which indicate increased semiquinone character. The greater semiquinone character in the BLPA complex correlates well with its high reactivity towards O2. Kinetic studies of the reaction of the BLPA complex with 1 atm O2 in CH3OH and CH2Cl2 under pseudo-first order conditions show that the BLPA complex reacts with O2 much slower than the TPA complex, where TPA is tris(2-pyridylmethyl)amine. It is presumably due to the steric effect of the methyl substituent on the pyridine ring. Nevertheless, both the high specificity and the fast kinetics can be rationalized on the basis of its low energy catecholate to FeⅢ charge transfer bands and large isotropic NMR shifts for the BLPA protons. These results provide insight into the nature of the oxygenation mechanism of the catechol dioxygenases.

Characteristics and Cancerostatic Activity of the Starfish Lectin (별불가사리 렉틴의 특성 및 암 세포 성장저해 효과)

  • Jeune, Kyung-Hee;Park, Chae-Soo;Park, Won-Hark;Choi, Soo-Jeong;So, Myung-Suk;Chung, See-Ryun
    • YAKHAK HOEJI
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    • v.41 no.4
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    • pp.421-432
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    • 1997
  • A new lectin was partially purified from starfish,Asterina pectinifera by means of physiological saline extraction, salt fractionation, ion exchange chromatography and hy droxyapatite chromatography, and it was named APL. The biochemical properties of the APL were characterized. In addition, its effects on lymphocyte mitogenicity and cancer cell agglutinability were tested. The APL agglutinated nonspecifically human erythrocytes and rabbit blood cells. Agglutinability was decreased to 30% of control activity below pH 5 and above pH 9 and was relatively unstable at increasing temperatures above 60$^{\circ}C$. The activity was reduced by addition of two kinds of metal ions, $Ba^{2+},\;Mn^{2+}$ and chelating agent, EDTA. APL was proved to be glycoproteins containing 9% sugars. For carbohydrate specificity, it was found that the activity of APL was inhibited by D(+)-glucosamine, D(+)-galactosamine, stachyose, N-acetyl-galactosamine and methyl-${\alpha}$-D-galactopyranoside among 35 sugars tested. In amino acid composition, the contents of acidic amino acids such as aspartic acid and glutamic acid were relatively high. This result suggest that the isoelectric point would be in a lower range. APL was found that it promotes the division of human lymphocytes. APL was proved to be a potent agglutinin for cancer cells such as HeLa, L929 and L1210 cells. Significant changes on the HeLa cell surfaces affected by APL were observed under the electron microscope.

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Characterization of a GH8 β-1,4-Glucanase from Bacillus subtilis B111 and Its Saccharification Potential for Agricultural Straws

  • Huang, Zhen;Ni, Guorong;Zhao, Xiaoyan;Wang, Fei;Qu, Mingren
    • Journal of Microbiology and Biotechnology
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    • v.31 no.10
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    • pp.1446-1454
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    • 2021
  • Herein, we cloned and expressed an endo-β-1,4-glucanase gene (celA1805) from Bacillus subtilis B111 in Escherichia coli. The recombinant celA1805 contains a glycosyl hydrolase (GH) family 8 domain and shared 76.8% identity with endo-1,4-β-glucanase from Bacillus sp. KSM-330. Results showed that the optimal pH and temperature of celA1805 were 6.0 and 50℃, respectively, and it was stable at pH 3-9 and temperature ≤50℃. Metal ions slightly affected enzyme activity, but chemical agents generally inhibited enzyme activity. Moreover, celA1805 showed a wide substrate specificity to CMC, barley β-glucan, lichenin, chitosan, PASC and avicel. The Km and Vmax values of celA1805 were 1.78 mg/ml and 50.09 µmol/min/mg. When incubated with cellooligosaccharides ranging from cellotriose to cellopentose, celA1805 mainly hydrolyzed cellotetrose (G4) and cellopentose (G5) to cellose (G2) and cellotriose (G3), but hardly hydrolyzed cellotriose. The concentrations of reducing sugars saccharified by celA1805 from wheat straw, rape straw, rice straw, peanut straw, and corn straw were increased by 0.21, 0.51, 0.26, 0.36, and 0.66 mg/ml, respectively. The results obtained in this study suggest potential applications of celA1805 in biomass saccharification.

Identification and Characterization of a Novel Thermostable GDSL-Type Lipase from Geobacillus thermocatenulatus

  • Jo, Eunhye;Kim, Jihye;Lee, Areum;Moon, Keumok;Cha, Jaeho
    • Journal of Microbiology and Biotechnology
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    • v.31 no.3
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    • pp.483-491
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    • 2021
  • Two putative genes, lip29 and est29, encoding lipolytic enzymes from the thermophilic bacterium Geobacillus thermocatenulatus KCTC 3921 were cloned and overexpressed in Escherichia coli. The recombinant Lip29 and Est29 were purified 67.3-fold to homogeneity with specific activity of 2.27 U/mg and recovery of 5.8% and 14.4-fold with specific activity of 0.92 U/mg and recovery of 1.3%, respectively. The molecular mass of each purified enzyme was estimated to be 29 kDa by SDS-PAGE. The alignment analysis of amino acid sequences revealed that both enzymes belonged to GDSL lipase/esterase family including conserved blocks with SGNH catalytic residues which was mainly identified in plants before. While Est29 showed high specificity toward short-chain fatty acids (C4-C8), Lip29 showed strong lipolytic activity to long-chain fatty acids (C12-C16). The optimal activity of Lip29 toward p-nitrophenyl palmitate as a substrate was observed at 50℃ and pH 9.5, respectively, and its activity was maintained more than 24 h at optimal temperatures, indicating that Lip29 was thermostable. Lip29 exhibited high tolerance against detergents and metal ions. The homology modeling and substrate docking revealed that the long-chain substrates showed the greatest binding affinity toward enzyme. Based on the biochemical and insilico analyses, we present for the first time a GDSL-type lipase in the thermophilic bacteria group.