• Title/Summary/Keyword: dimers

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Development of Purification Process of Recombinant Human Vascular Endotherial Growth Factor (VEGF) using Fusion Protein (융합 단백질을 이용한 재조합 인간 혈관내피세포 성장인자의 정제공정 개발)

  • Sung, Keehyun;Kim, In Ho
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.369-378
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    • 2017
  • Vascular endotherial growth factor (VEGF) is a potent mitogen that stimulates vascular permeability and angiogenesis and has a potential in therapeutic applications. An industrial production method that provides high yield as well as purity is needed. Researches for various factors of mild solubilization with combination of ubiquitin fusion protein to increase solubility were carried out as well as by changing pH and denaturant concentration. Usage of pET28-a bacteral expression vector in BL21 (DE3) host cell was capable of producing approximately 14 g/L VEGF fusion protein in 20L fermentor. A purification process consisting of four chromatography steps including refolding and digestion with UBP1 resulted in mild solublization under the conditions of 2M urea and pH 10.0 due to ubiquitin fusion tag protein that increases in solubility of target protein VEGF. High yield of refolding and dimerization could be obtained between two step Ni-affinity chromatography. Multimeric and misfolded proteins and endotoxin were removed by DEAE anion exchange chromatography. Final monomers were removed from dimers by gel filtration chromatography. Characterization analysis of purified dimeric VEGF was performed using SDS-PAGE and RP-HPLC with a purity of 97%.

Vitamin B12 Model Complexes: Synthesis and Characterization of Thiocyanato Cobaloximes and Thiocyanato Bridged Dicobaloximes of O-donor Ligands: DNA Binding and Antimicrobial Activity (비타민 B12 모델 착물: O-주개 리간드인 Thiocyanato Cobaloximes 및 Thiocyanato로 연결된 Dicobaloximes의 합성 및 특성규명: DNA 결합 및 향균 활성)

  • Mustafa, Bakheit;Satyanarayana, S.
    • Journal of the Korean Chemical Society
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    • v.54 no.6
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    • pp.687-695
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    • 2010
  • Complexes of thiocyanato(L)cobaloximes where L is urea, acetamide, semicrabazide and formamide were synthesized and characterized. The reaction of thiocyanato (L) cobaloximes (SCNCo$(DH)_2$(L)) with benzyl (aquo) cobaloxime $PhCH_2Co(DH)_2(OH_2)$ was found to produce a series of thiocyanato bridged dicobaloximes of a general formula of $PhCH_2Co(DH)_2SCNCo(DH_2)(L)$. Evidence for formulation as dicobaloximes containing thiocyanato ligand bridges was obtained from infrared data which show $20-45cm^{-1}$ increase in vCN upon formation of the dicobaloxime from the corresponding terminal thiocyanocobaloxime (SCNCo$(DH)_2$(L)). Further characterization of these two series was done on the basis of ($^1H$,$^{13}C$)NMR, LCMS and elemental analysis. Anti-microbial activity of thiocyanato(L)cobaloximes and thiocyanato bridged dicobaloximes were screened against E. Coli. The DNA-binding behaviors of both monomers and dimers were investigated by spectroscopic methods and viscosity measurements. The results indicated that the dimer complexes bind with calf-thymus DNA in an intercalative mode via the terminal benzyl ring into the base pairs of DNA. It was observed that the monomer complexes did not interact with DNA. Fluorescence spectra for the interaction between thiocyanato bridged dicobaloximes and DNA were also studied.

Analysis of Relationships Between Prethrombotic States and Cervical Cancer

  • Sun, You-Hong;Cui, Lin;Chen, Jue;Wang, Min;Liu, Jian-Jun;Liu, Xing-Xiang;Huang, Xin-En
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.6163-6166
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    • 2015
  • Objective: To analyze the relationship between a prethrombotic state and the occurrence of thrombosis, as well as survival time for patients with cervical cancer. Methods: Patients with first diagnosis of cervical cancer were subgrouped according to FIGO staging, and two D-dimer levels were assessed. According to the results, patients are divided into an observation group (abnormal) and control group (normal). Results: For 106 patients with cervical cancer, 38 with abnormal D-dimer, the abnormal rate is 35.9%, of which stage I accounted for 6.5%, stage II 38.5%, stage III 50%, and stage IV 61.1% (p=0.013); The level of D-dimers in stageI wass $0.87{\pm}0.68ug/ml$, while in stage II it was $1.50{\pm}1.35ug/ml$, stage III $2.60{\pm}1.86ug/ml$ and stage IV $18.6{\pm}53.4ug/ml$ (P=0.031); after follow-up of patients for 2-30 months, the mortality of observation group is 21.1%, while for control group it was 2.94% (p <0.01). In the observation group, survival time was $15.1{\pm}5.8$ months, while for control group it was $21.0{\pm}5.4$ months, the difference between two groups being highly significant (p=0.000). Conclusion: There is a direct correlation between prethrombotic state and the grade malignancy of cervical cancer. The level is positively correlated with clinical stage, and is inversely related to survival time, so that a prethrombotic state could be used to predict the prognosis for patients with cervical cancer.

Antioxidant Activity of Grape Seed Ethanol Extract According to Serial Solvent Fractionation (포도종실 에탄올 추출물의 순차 용매 분획에 따른 항산화 활성)

  • 정하열;윤수정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.6
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    • pp.1092-1096
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    • 2002
  • Ethyl acetate and butanol fractions among the serial solvent fractions of grape seed ethanol extract contained the catechin at the levels of 35.7 mg/g and 20.2 mg/g, respectively However, the POV increasing patterns of two linoleic acid samples containing each solvent fraction were so similar that the difference in antioxidant activity by the catechin content of each solvent fraction could not be found. Each solvent fraction was fractionated on C18 cartridges into three subfractions which were mono-, dimers fraction (FI), oligomers fraction (FII) and polymers fraction (FIII) to examine the effect by the difference in degree of Polymerization of proanthocyanidin. The catechin contents of ethyl acetate subfractions (E-F) were in the order of E-FI (26.0 mg/g) > E-FII (18.6 mg/g) > E-FIII (13.7 mg/g) but the three subfractions showed nearly similar antioxidant activities, by the POV measurement at 1,000 ppm concentration. Also the catechin contents of butanol subfractions (B-F) were in the order of B-FI (35.3 mg/g) > B-FII (30.8 mg/g) > B-FIII (22.7 mg/g) but similar antioxidant activities were observed in all subfractions. In this study, similar antioxidant activities of each solvent subfraction in spite of different catechin contents inform that the degree of polymerization of proanthocyanidin as well as the total catechin content should be considered in quality control of grape seed extract produced for natural antioxidant.

Construction and Production of Concatameric Human TNF Receptor-Immunoglobulin Fusion Proteins

  • Yim, Su-Bin;Chung, Yong-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.14 no.1
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    • pp.81-89
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    • 2004
  • Tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and lymphotoxin-$\alpha$ (LT-$\alpha$, TNF-$\beta$) can initiate and perpetuate human diseases such as multiple sclerosis (MS), rheumatoid arthritis (RA), and insulin-dependent diabetes mellitus (IDDM). TNFs can be blocked by the use of soluble TNF receptors. However, since monomeric soluble receptors generally exhibit low affinity or function as agonists, the use of monomeric soluble receptors has been limited in the case of cytokines such as TNF-$\alpha$, TNF-$\alpha$, interleukin (IL)-1, IL-4, IL-6, and IL-13, which have adapted to a multi component receptor system. For these reasons, very high-affinity inhibitors were created for the purpose of a TNFs antagonist to bind the TNFR and trigger cellular signal by using the multistep polymerase chain reaction method. First, recombinant simple TNFR-Ig fusion proteins were constructed from the cDNA sequences encoding the extracellular domain of the human p55 TNFR (CD120a) and the human p75 TNFR (CD120b), which were linked to hinge and constant regions of human $IgG_1$ heavy chain, respectively using complementary primers (CP) encoding the complementary sequences. Then, concatameric TNFR-Ig fusion proteins were constructed using recombinant PCR and a complementary primer base of recombinant simple TNFR-Ig fusion proteins. For high level expression of recombinant fusion proteins, Chinese hamster ovary (CHO) cells were used with a retroviral expression system. The transfected cells produced the simple concatameric TNFR-Ig fusion proteins capable of binding TNF and inactivating it. These soluble versions of simple concantameric TNFR-Ig fusion proteins gave rise to multiple forms such as simple dimers and concatameric homodimers. Simple TNFR-1g fusion proteins were shown to have much more reduced TNF inhibitory activity than concatameric TNFR-Ig fusion proteins. Concatameric TNFR-Ig fusion proteins showed higher affinity than simple TNFR-Ig fusion proteins in a receptor inhibitor binding assay (RIBA). Additionally, concatameric TNFR-Ig fusion proteins were shown to have a progressive effect as a TNF inhibitor compared to the simple TNFR-Ig fusion proteins and conventional TNFR-Fc in cytotoxicity assays, and showed the same results for collagen induced arthritis (CIA) in mice in vivo.

Sphingosine 1-Phosphate-induced Signal Transduction in Cat Esophagus Smooth Muscle Cells

  • Song, Hyun Ju;Choi, Tai Sik;Chung, Fa Yong;Park, Sun Young;Ryu, Jung Soo;Woo, Jae Gwang;Min, Young Sil;Shin, Chang Yell;Sohn, Uy Dong
    • Molecules and Cells
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    • v.21 no.1
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    • pp.42-51
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    • 2006
  • We investigated the mechanism of contraction induced by S1P in esophageal smooth muscle cells. Western blot analysis demonstrated that $S1P_1$, $S1P_2$, $S1P_3$, and $S1P_5$ receptors existed in the cat esophagus. Only penetration of EDG-5 ($S1P_2$) antibody into permeabilized cells inhibited S1P-induced contraction. Pertussis toxin (PTX) also inhibited contraction, suggesting that it was mediated by $S1P_2$ receptors coupled to a PTXsensitive $G_i$ protein. Specific antibodies to $G_{i2}$, $G_q$ and $G_{\beta}$ inhibited contraction, implying that the S1P-induced contraction depends on PTX-insensitive $G_q$ and $G_{\beta}$ dimers as well as the PTX-sensitive $G_{i2}$. Contraction was not affected by the phospholipase $A_2$ inhibitor DEDA, or the PLD inhibitor ${\rho}$-chloromercuribenzoate, but it was abolished by the PLC inhibitor U73122. Incubation of permeabilized cells with $PLC{\beta}3$ antibody also inhibited contraction. Contraction involved the activation of a PKC pathway since it was affected by GF109203X and chelerythrine. Since $PKC{\varepsilon}$ antibody inhibited contraction, $PKC{\varepsilon}$ may be required. Preincubation of the muscle cells with the MEK inhibitor PD98059 blocked S1P-induced contraction, but the p38 MAP kinase inhibitor SB202190 did not. In addition, co-treatment of cells with GF 109203X and PD98059 did not have a synergistic effect, suggesting that these two kinases are involved in the same signaling pathway. Our data suggest that S1P-induced contraction in esophageal smooth muscle cells is mediated by $S1P_2$ receptors coupled to PTX-sensitive $G_{i2}$ proteins, and PTX-insensitive $G_q$ and $G_{\beta}$ proteins, and that the resulting activation of the $PLC{\beta}3$ and $PKC{\varepsilon}$ pathway leads to activation of a p44/p42 MAPK pathway.

The Geometrical Isomerization on Acidification in Hexamolybdoheteropoly Oxometalate. The Crystal Structure of $(NH_{4})_{4.5}[H_{3.5}\alpha-PtMo_{6}O_{24}].\;1.5H_{2}O,\;(NH_{4})_{4}[H_{4}\beta-PtMo_{6}O_{24}].\;1.5H_{2}O,\;and\;K_{3.5}[H_{4.5}\alpha-PtMo_{6}O_{24}].\;3H_{2}O$

  • Lee, Uk;Yukiyoshi Sasaki
    • Bulletin of the Korean Chemical Society
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    • v.15 no.1
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    • pp.37-45
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    • 1994
  • $(NH_4)_{4.5}[H_{3.5}{\alpha}-PtMo_6O_{24}]{\cdot}1.5\;H_2O(A),\;(NH_4)_4[H_4{\beta}-PtMo_6O_{24}]{\cdot}1.5\;H_2O(B),\;and\;K_{3.5}[H_{4.5}{\alpha}-PtMo_6O_{24}]{\cdot}3\;H_2O(C)$ have been synthesized and their molecular structures have been also determined by single-crystal X-ray diffraction technique. The space groups, unit cell parameters, and R factors are as follows: Compound A, monoclinic, $A_{2/a}$, a= 19.074 (3), b=21.490 (3), c=15.183 (2) ${\AA};\;{\beta}$=109.67 (1) ${\AA}$; z=8; R=0.075($IF_0I>4{\sigma}(IF_0I);$ Compound B, triclinic, P$bar{1}$, a=10.776 (2), b=15.174 (4), c=10.697 (3) ${\AA};\;{\alpha}$ =126.29 (2), ${\beta}$=111.55 (2), ${\gamma}$=93.18 (2) ${\AA}$; Z=2; R=0.046($IF_0I>3{\sigma}(IF_0I);$): Compound C, triclinic, Pl, a=12.426 (2), b=13.884 (2), c=10.089 (1) ${\AA}$; ${\alpha}$=102.59 (2), ${\beta}$=110.73 (1), ${\gamma}$=53.93 (1) ${\AA}$; Z=2; R=0.074 ($IF_0I>3{\sigma}(IF_0I)$. Compounds A and C contain the well-known Anderson structure (planar structure) heteropoly oxometalate having approximate $bar{3}_m(D_{3d})$ symmetry, while compound B contains the bent structure heteropoly oxometalate having appproximate $2_{mm}(C2_v)$ symmetry. The bent structure and the planar one are geometrical isomers. These compounds are rot only novel heteroply molybdates containing platinate(IV) but also the first example of geometrical isomerism in the hexamolybdoheteropoly oxometalates. That isomerization surprisingly occurred because of the change of only 0.5 non-acidic hydrogen atom attached to the polyanion such as $[H_{3.5}{\alpha} -PtMo_6O_{24}]^{4.5-}{\to}[H_4{\beta}-PtMo_6O_{24}]^{4-}{\to}[H_{4.5}{\alpha} -PtMo_6O_{24}]^{3.5-}$. It seems that the gradual protonation of the polyanion plays an important role in that isomerism. These heteropolyanions form dimers by strong hydrogen bonds between two heteropolyanions in the respective crystal system.

Proliferative Effects of Flavan-3-ols and Propelargonidins from Rhizomes of Drynaria fortunei on MCF-7 and Osteoblastic Cells

  • Chang, Eun-Ju;Lee, Won-Jung;Cho, Sung-Hee;Choi, Sang-Won
    • Archives of Pharmacal Research
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    • v.26 no.8
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    • pp.620-630
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    • 2003
  • The proliferative effects of thirty Oriental medicinal herbs on MCF-7 (estrogen-sensitive breast cancer cell line) and ROS 17/2.8 osteoblast-like cells were determined using the MTT assay. Methanol extracts from several herbs was found to show proliferative activity on the above two cell lines in the range of 5 to 100 $\mu$g/mL. Among these active herbs, the methanol extract from the rhizomes of Drynaria fortunei showed the most potent proliferative activity, and the cell proliferations were significantly increase by 136 and 158% in the MCF-7 and ROS 17/2.8 cells, respectively, when treated with 100 $\mu$ g/mL. Through a bioassay-guided separation, eight flavonoids, including four new flavan-3-ols and two propelargonidins, together with the known (-)-epiafzelechin and naringin, were isolated. Their chemical structures were characterized as (-)-epiafzelechin (1), (-)-epiafzelechin-3-O-$\beta$-D-allopyranoside (2), (-)-epiafzelechin-3-O-(6"-O-acetyl)-$\beta$-D-allopyranoside (3), 4$\beta$-carboxymethyl-(-)-epiafzelechin methyl ester (4), 4$\beta$-car-boxymethyl-(-)-epiafzelechin sodium salt (5), naringin (6), (-)-epiafzelechin-(4$\beta$\rightarrow8)-4$\beta$-car-boxymethylepiafzelechin methyl ester (7) and (-)-epiafzelechin-($4\beta\rightarrow8, 2\beta\rightarrowΟ\rightarrow7)-epiafzelechin-(4\beta\righarrow8)-epiafzelechin (8) by extensive 1D and 2D NMR spectroscopy. Most of these flavonoids, in the range of $10^{-15}∼10^{-6}$ M, accelerated the proliferation of MCF-7 cell, with compounds 7 and 8, in the range of $10^{-15}∼10^{-12}$ M, showing especially potent proliferation effects. Meanwhile, seven flavonoids, with the exception of compound 4, stimulated the proliferation of ROS 17/2.8 cells in the range of $10^{-15}∼10^{-6}$ M, with compounds 5-8 especially accelerating the proliferation, in dose-dependent manners ($10^{-15}∼10^{-9}$ M), and their proliferative effect was much stronger than that of $E_2$ and genistein. These results suggest that propelargonidin dimers and trimers isolated from the rhizomes of Drynaria fortunei may be useful as potential phytoestrogens, which play important physiological roles in the prevention of postmenopausal osteoporosis.

Da-125 a New Antitumor Agent, Inhibits Topoisomerase II as Topoisomerase Poison and DNA Intercalator Simultaneously

  • Seo, Jin-Wook;Lee, Hak-Sung;Lee, Min-Jun;Kim, Mi-Ra;Shin, Cha-Gyun
    • Archives of Pharmacal Research
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    • v.27 no.1
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    • pp.77-82
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    • 2004
  • DA-125, a novel derivative of adriamycin, is known for its anti-cancer activity. In this study, the inhibitory mechanism of DA-125 on topoisomerase was investigated in the simian virus 40 (SV40) replicating CV-1 cell by studying the SV40 DNA replication intermediates and DNA-topoisomerase complexes. DNA-protein complexes that were formed in the drug-treated cells were quantitated by using a glass filter assay. SV40 DNA replication intermediates that were accumulated in the drug-treated CV-1 cell were analyzed in a high resolution gel. DA-125 did not accumulate B-dimers of SV40 DNA replication intermediates which were found in the adriamycin-treated CV-1 cells. DA-125 induced a dose-dependent formation of the DNA-protein complexes, while adriamycin did not. When adriamycin and etoposide (VP16) were added to the SV40-infected cells at the same time, adriamycin blocked the formation of the DNA-protein complexes induced by VP16 in a dose-dependent manner. However, DA-125 blocked the formation of the DNA-protein complexes induced by VP16 up to the maximum level of the DNA-protein complexes that were induced by DA-125 alone. Adriamycin and DA-125 did not inhibit the formation of the DNA-protein complexes that were caused by camptothecin, a known topoisomerase I poison. DA-125 is bifunctional in inhibiting topoisomerase II because it simultaneously has the properties of the topoisomerase II poison and the DNA intercalator. As a topoisomerase II poison, DA-125 alone induced dose-dependent formation of the DNA-protein complexes. However, as a DNA intercalator, it quantitatively inhibited the formation of the DNA-protein complexes induced by a strong topoisomerase II poison VP16. Furthermore considering that the levels of the DNA-protein complex induced by VP16 were decreased by DA-125 in terms of the topoisomerase II poison, we suggest that DA-125 has a higher affinity to the drug-binding sites of DNA than VP16 has.

Development of a Sunscreen Formulation that Increases UV Blocking Ability by UV Light (자외선에 의해 자외선 차단 효율이 상승하는 선크림 제형 개발)

  • Choi, Minsung;Cho, Hyeongjin;Song, Kyunghee;Song, Seungjin;Kang, Nae-Gyu;Park, Sun-Gyoo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.45 no.2
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    • pp.139-150
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    • 2019
  • This study is investigated sunscreen formulation that enhances UV absorption efficiency by UV light. Ethylhexyl methoxycinnamate (OMC) is one of the most common UV filters. Many studies have been conducted about photostability of OMC. It is well known that under the UV exposure, trans-OMC could turn to cis-OMC, or produce various photoproducts including its dimers. Those chemical structure changes were understood as the reason of a decrease in UV absorption efficiency upon UV exposure. However, it was found that OMC and isoamyl p-methoxycinnamate (IMC) could even enhance its UV absorption efficiency when it was exposed to UV light in an environment similar to actual use. In order to develop sunscreen formulation that enhances UV absorption efficiency by UV light, emollient with high polarity and compatibility should be avoided from the formular. Those emollient seemed to prevent OMC or IMC from producing photoproducts under UV light. Finally, a sunscreen formulation (UV sensing SPF boosting formular) enhancing UV absorption efficiency by UV was developed by the UV activated SPF boosting technology, and the effect of the sunscreen was evaluated. in vitro SPF of the sunscreen was increased from 50.69 to 72.33 when it was exposed to UV light and its in vivo SPF (53.7) was 56.10% higher than that of the control sunscreen (below 34.4).