• Title/Summary/Keyword: protein expression and purification

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Soluble Expression and Purification of Human Tissue-type Plasminogen Activator Protease Domain

  • Lee, Hak-Joo;Im, Ha-Na
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2607-2612
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    • 2010
  • Human tissue-type plasminogen activator (tPA) is a valuable thrombolytic agent used to successfully treat acute myocardial infarction, thromboembolic stroke, peripheral arterial occlusion, and venous thromboembolism. Recombinant tPA is accumulated as an inactive form in inclusion bodies of E. coli and is refolded in vitro, which is accompanied by extensive aggregation. In the present study, a tPA protease domain was expressed in an active soluble form in the cytosol of E. coli Rosetta-gami cells, which allowed disulfide bond formation and supplied the tRNA molecules required for six rarely used codons in E. coli. This strategy increased the amount of soluble protease domain protein and avoided the cumbersome refolding process. The purified protease domain not only degraded tPA substrate peptides but also formed a covalently bound complex with plasminogen activator inhibitor-1, as does full-length tPA. Soluble expression and purification of tPA domains may aid in functional analyses of this multi-domain protein, which has been implicated in many physiological and pathological processes.

Expression, Purification, and Characteristic of Tibetan Sheep Breast Lysozyme Using Pichia pastoris Expression System

  • Li, Jianbo;Jiang, Mingfeng;Wang, Yong
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.4
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    • pp.574-579
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    • 2014
  • A lysozyme gene from breast of Tibetan sheep was successfully expressed by secretion using a-factor signal sequence in the methylotrophic yeast, Pichia pastoris GS115. An expression yield and specific activity greater than 500 mg/L and 4,000 U/mg was obtained. Results at optimal pH and temperature showed recombinant lysozyme has higher lytic activity at pH 6.5 and $45^{\circ}C$. This study demonstrates the successful expression of recombinant lysozyme using the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, this study shows the feasibility of subsequent industrial manufacture of the enzyme with this expression system together with a high purity scheme for easy high-yield purification.

Overexpression and Purification of p24 and gp41 Proteins of Human Immunodeficiency Virus Type 1 in E. coli (대장균에서 인간면역결핍 바이러스 1형의 gag p24 및 env gp41 단백질의 과발현 및 정제)

  • Kim, Chae-Young;Shin, Soon-Cheon;Lee, Sung-Hee;Kim, Won-Bae;Kim, Byong-Moon
    • The Journal of Korean Society of Virology
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    • v.28 no.1
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    • pp.21-30
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    • 1998
  • Synthetic genes encoding the gag p24 and the part of the envelope protein gp41 of the human immunodeficiency virus (HIV-1) were cloned and overexpressed as fusion proteins in Escherichia coli, using an expression vector carrying T7 promoter and the poly-histidine leader, sequence. The overexpressed p24 fusion protein was purified by centrifugation, Ni-affinity chromatography and CM-sepharose chromatography. The overexpressed gp41 fusion protein was purified by centrifugation, $C_4$ chromatography and DEAE-sepharose chromatography. The purified fusion proteins showed a high level of purity and immunoreactivity in SDS-polyacrylamide gel electrophoresis and western blot analysis. These results suggest that this prokaryotic - expression purification method is suitable for obtaining a large amount of the viral antigen which may be useful for screening of antibodies to HIV-1 in human blood samples.

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Optimization of Expression, Purification, and NMR Measurement for Structural Studies of Syndecan-4 Transmembrane Region

  • Park, Tae-Joon;Lee, Min-Hye;Choi, Sung-Sub;Kim, Yong-Ae
    • Journal of the Korean Magnetic Resonance Society
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    • v.15 no.1
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    • pp.25-39
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    • 2011
  • Syndecan-4 is a transmembrane heparan sulfate proteoglycan, which is a coreceptor with integrins in cell adhesion. To get better understand the mechanism and function of Syndecan-4, it is critical to elucidate the three-dimensional structure of a single transmembrane spanning region of them. Unfortunately, it is hard to prepare the peptide because syndecan-4 is membrane-bound protein that transverse the lipid bilayer of the cell membrane. Generally, the preparation of transmembrane peptide sample is seriously difficult and time-consuming. In fact, high yield production of transmembrane peptides has been limited by experimental adversities of insufficient yields and low solubility of peptide. Here, we demonstrate experimental processes and results to optimize expression, purification, and NMR measurement condition of Syndecan-4 transmembrane peptide.

Recombinant Expression, Isotope Labeling, and Purification of Cold shock Protein from Colwellia psychrerythraea for NMR Study

  • Moon, Chang-Hun;Jeong, Ki-Woong;Kim, Hak-Jun;Heo, Yong-Seok;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2647-2650
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    • 2009
  • Cold shock proteins (Csps) are a subgroup of the cold-induced proteins on reduction of the growth temperature below the physiological temperature. They preferentially bind to single-stranded nucleic acids to translational regulation via RNA chaperoning. Csp plays important role in cold adaptations for the psychrophilic microorganism. Recently, Cold shock protein from psychrophilic bacteria, Colwellia psychrerythraea (CpCsp) has been identified. Three dimensional structures of a number of Csps from various microorganisms have been solved by NMR spectroscopy or X-ray crystallography, but structures of psychrophilic Csps were not studied yet. Therefore, cloning and purification protocols for further structural study of psychrophilic Csp have been optimized in this study. CpCsp was expressed in E. coli with pET-11a vector system and purified by ion exchange, size exclusion, and reverse phase chromatography. Expression and purification of CpCsp in M9 minimal media was carried out and $^{15}N$-labeled proteins with high purity over 90% was obtained. Further study will be carried out to investigate the tertiary structure and dynamics of CpCsp.

Expression and Purification of Recombinant Human Bone Morphogenetic Protein-7 (rhBMP-7) in Bacillus subtilis (고초균을 이용한 재조합 인간 골 형성 단백질-7의 발현과 정제)

  • Kim, Chun-Kwang;Oh, Sung-Duk;Rhee, Jong-Il
    • KSBB Journal
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    • v.25 no.3
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    • pp.257-264
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    • 2010
  • Bone morphogenetic protein-7 (BMP-7) is one of important growth factors for skeletal development and bone growth. In this work, BMP-7 was efficiently expressed in recombinant Bacillus subtilis. The mature BMP-7 protein indicated molecular weight of 15.4 kDa by Western blot assay and was secreted into culture medium with 0.35 ng/mL. The extracellular and intracellular rhBMP-7 proteins were purified by using a FPLC system with an ion exchange column and a gel filtration column. The extracellular and intracellular rhBMP-7 proteins had finally a 57.1% purity and a 36.2% purity, respectively. The purified rhBMP-7 proteins showed an intact biological activity which stimulated alkaline phophatase (ALP) activity in MC3T3-E1 cells.

Expression and Purification of Toll-like Receptor 9 Cytoplasmic Domain in Pichia patoris (Pichia pastoris로부터 Toll-like Receptor 9의 세포 내 도메인 단백질의 발현과 순수분리 정제)

  • Lee Kyun-Young;Lee Kon-Ho
    • Journal of Plant Biotechnology
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    • v.32 no.4
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    • pp.269-273
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    • 2005
  • Toll-like receptors (TLR) are important components of innate immunity in the defense against pathogens. TLRs recognize pathogen-associated common molecular patterns. TLRs are similar to the receptors involved in defense responses in plants. TLR protein is a type 1 membrane protein, consisting of an extracellular domain containing leucine-rich repeats and a cytoplasmic domain. The cytoplasmic domain delivers ligand recognition signals that result in production of anti-microbial agents. The cytoplasmic domain (amino acid 858-1032) of toll-like receptor 9 has been expressed using methylotrophic yeast Pichia pastoris. The protein expression was confirmed by Western-blot, N-terminal sequencing and MALDl-TOF mass spectrometry. The proteins have been purified by nickel affinity, cation exchange and gel-filtration chromatography.

Expression of Polyhistidine-Containing Fusion Human HepG2 Type Glucose Transport Protein in Spodoptera Cells and Its Purification Using a Metal Affinity Chromatography

  • Lee, Chong-Kee
    • Biomedical Science Letters
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    • v.16 no.3
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    • pp.201-206
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    • 2010
  • In order to develop procedures for the rapid isolation of recombinant sugar transporter in functional form from away from the endogenous insect cell transporter, gene fusion techniques were exploited. Briefly, BamH1-digested human HepG2 type glucose transport protein cDNA was first cloned into a transfer vector pBlueBacHis, containing a tract of six histidine residues. Recombinant baculoviruses including the human cDNA were then generated by allelic exchange following transfection of insect cells with wild-type BaculoGold virus DNA and the recombinant transfer vector. Plaque assay was then performed to obtain and purify recombinant viruses expressing the human transport protein. All the cell samples that had been infected with viruses from the several blue plaques exhibited a positive reaction in the immnuassay, demonstrating expression of the glucose transport protein. In contrast, no color development in the immunoassay was observed for cells infected with the wild-type virus or no virus. Immunoblot analysis showed that a major immunoreactive band of apparent Mr 43,000~44,000 was evident in the lysate from cells infected with the recombinant baculovirus. Following expression of the recombinant fusion protein with the metal-binding domain and enterokinase cleavage site, the fusion protein was recovered by competition with imidizole using immobilized metal charged resin. The leader peptide was then removed from the fusion protein by cleavage with porcine enterokinase. Final separation of the recombinant protein of the interest was achieved by passage over $Ni^{2+}$-charged resin under binding conditions. The expressed transport protein bound cytochalasin B and demonstrated a functional similarity to its human counterpart.

Preliminary Research on the Expression, Purification and Function of the Apoptotic Fusion Protein, Sival

  • Zhang, Ya-Han;Yu, Lu-Gang;Zhu, Wan-Zhan;Wang, Sheng-Li;Wang, Dian-Dong;Yang, Yan-Xin;Yu, Xia
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8685-8688
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    • 2014
  • The objective of the present study was to investigate cloning, expression, and functions of the recombinant protein, Siva1. Siva1 gene was synthesized by RT-PCR from HCT116 cells. Plasmids were cleaved with the restriction endonuclease, BamH1/Sal1 and products were connected to pQE30, which underwent cleavage by BamH1/Sal1. The recombinant plasmid, pQE30-Siva1, was identified after digestion with restriction endonucleases followed by transformation into E. coli M15. Expression of Siva1 was induced by IPTG and identified by SDS-PAGE following purification with affinity chromatography. The results showed that size of Siva1 was 12 kDa, consistent with the molecular weight of the His-Siva1 fusion protein. Functional test demonstrated that Siva1 significantly inhibited the invasion and migration of HCT116 cells. It may thus find clinical application for control of cancers.