• Title/Summary/Keyword: skc

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Heterologous Production of Streptokinase in Secretory Form in Streptomyces lividans and in Nonsecretory Form in Escherichia coli

  • Kim,, Mi-Ran;Choeng, Yong-Hoon;Chi, Won-Jae;Kang, Dae-Kyung;Hong, Soon-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.132-137
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    • 2010
  • The skc gene encoding streptokinase (SK) with a molecular mass of approximately 47.4 kDa was cloned from Streptococcus equisimilis ATCC 9542 and heterologously overexpressed in Streptomyces lividans TK24 and E. coli using various strong promoters. When the promoter for sprT [Streptomyces griseus trypsin (SGT)] was used in the host S. lividans TK24, a 47.4-kDa protein was detected along with a smaller hydrolyzed protein (44 kDa), suggesting that posttranslational hydrolysis had occurred as has been reported in other expression systems. The casein/plasminogen plate assay revealed that the plasmid construct containing the SGT signal peptide was superior to that containing the SK signal peptide in terms of SK production. Maximal production of SK was calculated to be about 0.25 unit/ml of culture broth, a value that was five times higher than that obtained with other expression systems using ermE and tipA promoters in the same host. When the skc gene was expressed in E. coli BL21(${\Delta}DE3$)pLys under the control of the T7 promoter, a relatively large amount of SK was expressed in soluble form without hydrolysis. SK activity in E. coli/pET28a-$T7_pSK_m$ was more than 2 units/ml of culture broth, even though about half of the expressed protein formed an inactive inclusion body.

Effect of Co-monomer on the Physical Properties of Poly(ethylene naphthalate) Copolymer (단량체의 종류에 따른 폴리(에틸렌 나프탈레이트) 공종합체의 물성 연구)

  • Kim, Jae-Hyun;Heo, Hye-Young;Jung, Tae-Houng;Han, Joon-Hee;Kang, Ho-Jong
    • Polymer(Korea)
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    • v.35 no.2
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    • pp.146-151
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    • 2011
  • The physical properties of poly (ethylene 2,6-naphthalate) (PEN) copolymers were studied. PEN copolymers were synthesized successfully from the mixtures of ethylene glycol(EG), 1,3-propanediol (PD) and l,4-butanediol (BD) with 2,6-dimethyl naphthalene dicarboxylate. The results indicated that PEN copolymers showed an amorphous state when the content of BD(PD) in applied EG/BD(EG/PD) mixtures was less than 40% during the polycondensation. As a result, the lowering of thermal properties, orientation, and mechanical properties was found, however, the dimensional stability was improved. This is a promising result to apply the synthesized PEN copolymers as flexibles substrates.

Dimensional Stability of Poly(ethylene/propylene naphthalate) as a Flexible Substrate Application (유연 기판 소재로 응용을 위한 폴리(에틸렌/프로필렌 나프탈레이트)의 치수안정성 연구)

  • Kim, Jae-Hyun;Heo, Hye-Young;Jung, Tae-Houng;Han, Joon-Hee;Kang, Ho-Jong
    • Polymer(Korea)
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    • v.33 no.4
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    • pp.371-376
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    • 2009
  • The 1,3-propane diol has been introduced as a co-monomer with ethylene glycol to polymerize the poly(ethylene/propylene naphthalate) in order to improve the dimensional stability of poly(ethylene naphthalate) for a possible flexible substrate material. Based on $^1H$-NMR results, it was found that poly (ethylene/propylene naphthalate) has been synthesised successfully. Introducing 1,3-propane diol resulted in the amorphous state in polyester as well as lowering of glass transition and thermal degradation temperature. Coexisting relatively longer propylene segment compared with ethylene in synthesized polyester caused less orientation behavior and reducing thermal expansion coefficient. This is a promising result for poly (ethylene/propylene naphthalate) to apply a flexible substrate.

New Yellow Quinoline Derivatives Including Dione Moiety for Image Sensor Color Filters (이미지 센서 컬러 필터용 다이온 성분을 포함하는 신규 황색 퀴놀린 유도체)

  • Sunwoo, Park;Seyoung, Oh;Yuna, Kang;Hyukmin, Kwon;Sunwoo, Dae;Changyu, Lee;Dae Won, Kim;Min-Sik, Jang;Jongwook, Park
    • Applied Chemistry for Engineering
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    • v.34 no.1
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    • pp.80-85
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    • 2023
  • New yellow quinoline-dione dye derivatives were designed and synthesized for use in image sensor color filters. The synthesized compounds have a basic chemical structure composed of quinoline and dione groups. New materials were evaluated on the basis of their optical and thermal properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performances revealed that, between the two prepared compounds, 2-(3-hydroxyquinolin-2(1H)-ylidene)-1H-indene-1,3(2H)-dione (HQIDO) exhibited the superior performance as an image sensor color filter material, including a solubility greater than 0.5 wt% in propylene glycol monomethyl ether acetate solvent and a high decomposition temperature of 298 ℃, respectively. The results suggest that HQIDO can be used as a yellow dye additive in an image sensor colorant.