• Title/Summary/Keyword: Biologically-active

검색결과 549건 처리시간 0.027초

Expression, Purification, and Biological Characterization of The Amino-Terminal Fragment of Urokinase in Pichia pastoris

  • Li, Jianping;Lin, Yuli;Zhuang, Hongqin;Hua, Zi-Chun
    • Journal of Microbiology and Biotechnology
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    • 제23권9호
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    • pp.1197-1205
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    • 2013
  • Urokinase (uPA) and its receptor (uPAR) play an important role in tumor growth and metastasis. Targeting the excessive activation of this system as well as the proliferation of the tumor vascular endothelial cell would be expected to prevent tumor neovasculature and halt the tumor development. In this regard, the amino-terminal fragment (ATF) of urokinase has been confirmed as effective to inhibit the proliferation, migration, and invasiveness of cancer cells via interrupting the interaction of uPA and uPAR. Previous studies indicated that ATF expressed in Escherichia coli was mainly contained in inclusion bodies and also lacked posttranslational modifications. In this study, the biologically active and soluble ATF was cloned and expressed in Pichia pastoris. The recombinant protein was purified to be homogenous and confirmed to be biologically active. The yield of the active ATF was about 30 mg/l of the P. pastoris culture medium. The recombinant ATF (rATF) could efficiently inhibit angiogenesis, endothelial cell migration, and tumor cell invasion in vitro. Furthermore, it could inhibit in vivo xenograft tumor growth and prolong the survival of tumor-bearing mice significantly by competing with uPA for binding to cell surfaces. Therefore, P. pastoris is a highly efficient and cost-effective expression system for large-scale production of biologically active rATFs for potential therapeutic application.

효모에서 활성형의 곤충유래 항균펩티드 defensin의 발현 (Expression of Biologically Active Insect-Derived Antibacterial Peptide, Defensin, in Yeast)

  • 강대욱;안순철;김민수;안종석
    • 생명과학회지
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    • 제12권4호
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    • pp.477-482
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    • 2002
  • 효모 glucoamylase의 promoter와 분비신호서열 그리고 MF$\alpha$1의 prosequence를 이용하여 곤충 defensin을 S. cerevisiae 2805에서 항균활성을 보유한 형태로 발현 및 분비하는데 성공하였다. 발현된 defensin의 대부분이 세포 외로 분비되어 거의 모든 항균활성이 배양 상등액에 존재하였다. 이것은 S. cerevisiae에서 발현된 defensin이 glucoamylase의 분비신호서열과 MF$\alpha$1의 prosequenre에 의해 효율적으로 processing되어 분비됨을 시사한다. Defensin의 다른 미생물에 대한 항균활성을 조사한 결과 병원균인 St. aureus와 L. monocytogenes에 대해서도 항균활성이 존재하였다.

Synthesis of Biologically Active Chalcones and their Anti-inflammatory Effects

  • Jeon, Jae-Ho;Kim, Si-Jun;Kim, Cheol-Gi;Kim, Jin-Kyung;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
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    • 제33권3호
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    • pp.953-957
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    • 2012
  • Chalcones have been reported to have various biological activities including antitumor, antiparasitic, antileishmanial, antioxidative, superoxide scavenging, antibacterial, and PTP1B activity. Due to the limited natural resources, we had to prepare sizable quantities of biologically active chalcones for bio-tests. Therefore, Claisen-Schmidt condensation between substituted acetophenones and corresponding aldehydes enabled us to prepare chalcones for inflammatory studies. Chalcones thus prepared showed significant suppression of nitric oxide (NO) production at $10{\mu}M$.

Bone Replacement and Grafting with a Biologically Active Ceramic Composite

  • McGee, Thomas Donald
    • The Korean Journal of Ceramics
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    • 제7권1호
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    • pp.41-44
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    • 2001
  • A composite of $Ca_3$(PO$_4$)$_2$ and MgAl$_2$O$_4$ spinel is biologically active and has enduring strength. Its strength depends on the spinel phase. The flaws in the spinel depend on the grain size of the calcium phosphate phase and are not altered by dissolution. The calcium phosphate, ${\alpha}$ tri-calcium phosphate, controls the tissue response. Bone bonds to the implant. A design for a bone graft as a replacement for a section of the diaphysis of a canine femur provides for tensile, compressive, torsional and bending load; and for the physiological processes of bonding and remodeling. A bone plate, used to stabilize the implant at time of surgery was removed after about one year. Over seven years of service have been achieved without internal or external fixation.

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Effects of Co-Expression of Liver X Receptor β-Ligand Binding Domain with its Partner, Retinoid X Receptor α-Ligand Binding Domain, on their Solubility and Biological Activity in Escherichia coli

  • Kang, Hyun
    • Journal of Microbiology and Biotechnology
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    • 제25권2호
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    • pp.247-254
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    • 2015
  • In this presentation, I describe the expression and purification of the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a commercially available double cistronic vector, pACYCDuet-1, to express the receptor heterodimer in a single cell as the soluble form. I describe here the expression and characterization of a biologically active heterodimer composed of the liver X receptor β-ligand binding domain and retinoid X receptor α-ligand binding domain. Although many of these proteins were previously seen to be produced in E. coli as insoluble aggregates or "inclusion bodies", I show here that as a form of heterodimer they can be made in soluble forms that are biologically active. This suggests that co-expression of the liver X receptor β-ligand binding domain with its binding partner improves the solubility of the complex and probably assists in their correct folding, thereby functioning as a type of molecular chaperone.

Bioactive Conjugated Linoleic Acid (CLA) in Milk

  • Kee, Jun-Ill;Ganesan, Palanivel;Kwak, Hae-Soo
    • 한국축산식품학회지
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    • 제30권6호
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    • pp.879-885
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    • 2010
  • Conjugated linoleic acid (CLA) isomers are found naturally in foods, such as milk, milk products, beef and others, from biohydrogenation of vegetable oils. They are heterogenous group of isomers of linoleic acid in the family of polyunsaturated fatty acids. Among the isomers of linoleic acid cis9, trans11- CLA (c9, t11-CLA) and trans10, cis12- CLA (t10, c12-CLA) are found to be biologically active isomers. These biologically active isomers either individual or combined found to be health beneficial in various diseases, such as cancer, diabetes, obesity, and atherosclerosis, conclusive participation in physiological processes are necessary. This review focused on the current study of CLA in prevention of disease, such as cancer, diabetes and atherosclerosis, and their effective function in body fat reduction, improvement of bone and muscle mass at a cellular, clinical and systematic level.

Synthesis of Water-Soluble Aminoaryloxy-Methylamino Cosubstituted Polyphosphazenes as Carrier Species for Biologically Active Agents

  • 권석기
    • Bulletin of the Korean Chemical Society
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    • 제22권11호
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    • pp.1243-1247
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    • 2001
  • The water-soluble poly(aminoaryloxy-methylamino phosphazene) has been synthesized and investigated as a polymeric carrier species for the covalent attachment of biologically active agents. The cyclic trimeric model systems were utilized for the synthesis of polymeric analogues containing bioactive side groups. The sodium salt of 4-acetamidophenol was first allowed to react with (NPCl2)3 or (NPCl2)n and was then treated with excess methylamine to yield derivatives of type [NP(NHCH3)x(OArNHCOCH3)y]3 or [NP(NHCH3)x(OArNHCOCH3)y]n. The 4-acetamido groups were then hydrolyzed to 4-aminophenoxy units with potassium tert-butoxide. Coupling reactions between amino group and N-acetylglycine was accomplished with the use of dicyclohexylcarbodiimide. Their properties and structural characterization are discussed.