scholarly journals CLONAGEM, EXPRESSÃO E CARACTERIZAÇÃO DA NUCLEOPROTEÍNA RECOMBINANTE DO VÍRUS DA BRONQUITE INFECCIOSA EM ESCHERICHIA COLI E EM PICHIA PASTORIS

2010 ◽  
Vol 77 (1) ◽  
pp. 1-9
Author(s):  
A.M. Gibertoni ◽  
M.C.M. Gonçalves ◽  
M.F.S. Montassier ◽  
C.C. Fernandes ◽  
H.J. Montassier

RESUMO O gene da proteína de nucleocapsídeo (1.230 pb) da estirpe M41 do vírus da bronquite infecciosa (VBI) foi amplificado pelas reações de transcrição reversa e em cadeia da polimerase (RT-PCR) e clonado, em seguida, em dois sistemas; pET28a - Escherichia coli e pFLD -Pichia pastoris. Os produtos recombinantes construídos para expressão (pET28a-N ou pFLD-N) foram identificados por análises de PCR e de sequenciamento de nucleotídeos. Os clones transformantes da linhagem BL21 de E. coli e da linhagem GS115 de P. pastoris foram submetidos aos protocolos apropriados de indução. A expressão da proteína N de fusão com etiqueta de poli-histidina e com massa molecular de 54 kDa foi determinada pelas técnicas de SDS-PAGE e de Western blotting, confirmando-se que ambas proteínas N recombinantes apresentaram tamanhos e antigenicidade compatíveis com a proteína N nativa do próprio VBI. O sistema E. coli expressou uma quantidade relevante da proteína N recombinante, enquanto que o sistema P. pastoris produziu uma baixa recuperação dessa proteína recombinante. A proteína N recombinante gerada pelo sistema bacteriano foi purificada em resina de níquel-sepharose. O conjunto de resultados indica que o sistema de expressão constituído por pET28a – E. coli é mais efetivo para produzir a proteína N recombinante do VBI destinada ao uso como antígeno para detectar anticorpos anti-virais específicos em ensaios de imunodiagnóstico para essa infecção viral.

2016 ◽  
Vol 4 (1) ◽  
pp. 81
Author(s):  
Paula Fonseca Finger ◽  
Luana Alves Dummer ◽  
Michele Soares Pepe ◽  
Carolina Georg Magalhães ◽  
Paulo Augusto Esteves ◽  
...  

A bronquite infecciosa das galinhas (IB) é uma enfermidade altamente contagiosa que acomete aves de todas as idades e causa grandes prejuízos na avicultura. O trabalho descreve uma metodologia para expressão da glicoproteína S1 do vírus da bronquite infecciosa das galinhas (IBV) em Pichia pastoris e Escherichia coli. Para P. pastoris o gene foi amplificado por RT-PCR, com posterior clonagem e expressão no vetor pPICZαB. Para E. coli, foi elaborado o gene sintético a partir de uma sequência consenso de amostras de campo nacionais e internacionais, clonado e expresso no vetor pAE. Após indução dos clones, a proteína S1 foi identificada pelas técnicas de Dot blotting e Western blotting. A proteína expressa apresentou reatividade frente a soros de aves positivas para IBV, evidenciando sua antigenicidade.


1996 ◽  
Vol 10 (2) ◽  
pp. 187-194 ◽  
Author(s):  
D. Deutsch ◽  
E. Chityat ◽  
M. Hekmati ◽  
A. Palmon ◽  
Y. Farkash ◽  
...  

A human cDNA, encoding for the 175-aminoacid human amelogenin, was prepared by RT PCR from tooth bud mRNA and sub-cloned into pGEX-KG expression plasmid for over-expression in E. coli. The expressed protein was characterized by SDS-PAGE, Western blotting, and N-terminal amino acid sequencing.


Author(s):  
Katayoun DASTAN ◽  
Mehdi ASSMAR ◽  
Nour AMIRMOZAFARI ◽  
Fariborz Mansour GHANAEI ◽  
Mirsasan MIRPOUR

Background: Strongyloidiasis is a public health concern in northern regions of Iran, caused by Strongyloides stercoralis. Auto-infection cycle can be resulted in high parasitic load, especially in immunocompromised hosts. Because of low sensitivity of stool culture and stool-based microscopy techniques, detection of antibodies in patient’s sera can be an alternative diagnostic technique for detection of the nematode. In the present study, as the first step of the development of an ELISA kit for the detection of antibodies against the nematode, IgG4 immunoreactive protein (NIE) was expressed in Escherichia coli expression system, purified and verified. Methods: The NIE gene sequence was retrieved from the GenBank. This sequence was codon-optimized for the expression in E. coli BL21 (DE3). The sequence was inserted into the expression vector pET-30b (+). The recombinant vector was then transferred into competent E. coli BL21 (DE3). Transformed colonies were selected and verified by colony PCR. NIE gene expression was induced with IPTG induction. The protein production was evaluated by SDS-PAGE and verified using Western blotting. Results: The codon-optimized NIE gene had required parameters for expression in E. coli. NIE protein was proved and verified by SDS-PAGE and Western blotting.  Conclusion: NIE recombinant protein was successfully expressed in E. coli expression system in appropriate amounts. The recombinant protein can be used for developing ELISA kit in diagnosis of S. stercoralis.


2015 ◽  
Vol 16 (1) ◽  
pp. 31
Author(s):  
Kusdianawati Kusdianawati ◽  
Apon Zaenal Mustopa ◽  
Suharsono Suharsono ◽  
Bugi Ratno Budiarto ◽  
Fatimah Fatimah ◽  
...  

Plantaricin is one of bacteriocins that have the potential to be used as food preservative. Plantaricin is safe for human consumption because it can be easily degraded by proteolytic enzymes. The objective of this study was to express and purify recombinant pre-mature peptide of plantaricin F from <em>Lactobacillus plantarum</em> S34 in <em>Escherichia coli</em>. Plantaricin gene-specific primer was used to obtain pln F structural gene amplicon from L. <em>plantarum</em> S34. This amplicon was cloned in pET32a vector and expressed in E. coli BL21 (DE3) pLysS. Pre-mature plantaricin F peptide was expressed as Histagged-fusion protein and separated by Co2+-chelating affinity chromatography. L. <em>plantarum</em> S34-derived pre-mature plantaricin F peptide fused with thioredoxin-(His)6tag had successfully been expressed in E. <em>coli</em> BL21 (DE3) pLysS using pET32a as an expression vector. The fused recombinant pln F as pre-mature state expressed had a molecular mass of +24 kDa, meanwhile the fused recombinant that contained only the leader peptide of pln F appeared as +20 kDa based on SDS-PAGE separations. The optimal production of fused recombinant pln F as soluble fraction was obtained when culture condition was added with 0.5 mM of IPTG and incubated at 22°C for 5 hours (OD~1). Furthermore, the expression of fused recombinant pln F as its pre-mature peptide pointed out that the pln F’s leader peptide could be proteolytically cleaved by a system in heterologous cells. Overall, heterologous pln F production as pre-mature peptide fused with thioredoxin-(His)6tag had been well established. From this research, we expect plantaricin F can be expressed and purified in E. coli.


2020 ◽  
Vol 23 (3) ◽  
pp. 665-672
Author(s):  
Giang Huong Ta ◽  
Huy Quoc Nguyen ◽  
Quan Dang Nguyen

Introduction: CD45 is a common marker of leukocytes. Anti-human CD45 monoclonal antibody (MAb) has been used widely in diagnosing and monitoring hematologic diseases. The aim of this study was to generate an anti-human CD45 MAb, which can be used in research and diagnosis. Methods: Recombinant human CD45RO antigen was expressed from E. coli BL21 (DE3), purified and analyzed by SDS-PAGE and Western blotting. The purified CD45RO antigen was used to immunize Balb/c mice. Spleen cells from immunized mouse were collected and fused with P3X63Ag8.653 myeloma cells to form hybridoma. Anti-CD45 antibody-secreting capacity of hybridoma clones was evaluated by ELISA assay. Anti-CD45 MAb from the culture supernatant of the chosen hybridoma clone was purified by affinity chromatography. The MAb was characterized the biochemical characteristics and biological activity. Results: Recombinant human CD45RO antigen was expressed and purified from E.coli BL21 (DE3). Injection of purified CD45RO antigen provoked the immune response in Balb/c mice. Hybridoma clones were generated successfully by the fusion of spleen cells from the selected immunized-mouse and myeloma cells. Among these hybridoma clones, one with the highest yield of MAb production was identified. The isotype of the anti-CD45 MAb created in this work is IgG2b, while its the light chain is kappa (k) type. The affinity of this MAb with CD45RO antigen is high with Kd value at the picomolar level. The anti-CD45 MAb can interact with CD45 naturally expressed on the surface of Jurkat cells in Western blotting and fluorescent immuno-staining assay. Conclusion: We have developed successfully an anti-human CD45 MAb using hybridoma technology, which can recognize CD45 in ELISA, Western blotting, and fluorescent immuno-staining analysis. Although further investigations are necessary, obviously, our anti-human CD45 MAb is potential for research and diagnosis applications.


Author(s):  
Nguyen Thi My Trinh ◽  
Tran Linh Thuoc ◽  
Dang Thi Phuong Thao

Background: The recombinant human granulocyte colony stimulating factor con-jugated with polyethylene glycol (PEGylated GCSF) has currently been used as an efficient drug for the treatment of neutropenia caused by chemotherapy due to its long circulating half-life. Previous studies showed that Granulocyte Colony Stimula-ting Factor (GCSF) could be expressed as non-classical Inclusion Bodies (ncIBs), which contained likely correctly folded GCSF inside at low temperature. Therefore, in this study, a simple process was developed to produce PEGylated GCSF from ncIBs. Methods: BL21 (DE3)/pET-GCSF cells were cultured in the LiFlus GX 1.5 L bioreactor and the expression of GCSF was induced by adding 0.5 mM IPTG. After 24 hr of fermentation, cells were collected, resuspended, and disrupted. The insoluble fraction was obtained from cell lysates and dissolved in 0.1% N-lauroylsarcosine solution. The presence and structure of dissolved GCSF were verified using SDS-PAGE, Native-PAGE, and RP-HPLC analyses. The dissolved GCSF was directly used for the con-jugation with 5 kDa PEG. The PEGylated GCSF was purified using two purification steps, including anion exchange chromatography and gel filtration chromatography. Results: PEGylated GCSF was obtained with high purity (~97%) and was finally demonstrated as a form containing one GCSF molecule and one 5 kDa PEG molecule (monoPEG-GCSF). Conclusion: These results clearly indicate that the process developed in this study might be a potential and practical approach to produce PEGylated GCSF from ncIBs expressed in Escherichia coli (E. coli).


2020 ◽  
Vol 75 (5) ◽  
pp. 1151-1158
Author(s):  
Corey S Suelter ◽  
Nancy D Hanson

Abstract Background Virulence genes and the expression of resistance mechanisms undoubtedly play a role in the successful spread of the pandemic clone Escherichia coli ST131. Porin down-regulation is a chromosomal mechanism associated with antibiotic resistance. Translation of porin proteins can be impacted by modifications in mRNA half-life and the interaction among small RNAs (sRNAs), the porin transcript and the sRNA chaperone Hfq. Modifications in the translatability of porin proteins could impact the fitness and therefore the success of E. coli ST131 isolates in the presence of antibiotic. Objectives To identify differences in the translatability of OmpC and OmpF porins for different STs of E. coli by comparing steady-state RNA levels, mRNA half-life, regulatory sRNA expression and protein production. Methods RNA expression was evaluated using real-time RT–PCR and OmpC mRNA half-life by northern blotting. OmpC, OmpF and Hfq protein levels were evaluated by immunoblotting. Results Differences between ST131 and non-ST131 isolates included: (i) the level of OmpC RNA and protein produced with mRNA expression higher for ST131 but OmpC protein levels lower compared with non-ST131 isolates; (ii) OmpC mRNA half-life (21–30 min for ST131 isolates compared with &lt;2–23 min for non-ST131 isolates); and (iii) levels of the sRNA MicC (2- to 120-fold for ST131 isolates compared with −4- to 70-fold for non-ST131 isolates). Conclusions Mechanisms involved in the translatability of porin proteins differed among different STs of E. coli. These differences could provide a selective advantage to ST131 E. coli when confronted with an antibiotic-rich environment.


Blood ◽  
1989 ◽  
Vol 73 (5) ◽  
pp. 1202-1206 ◽  
Author(s):  
MG Bolyard ◽  
ST Lord

Abstract The human fibrinogen B beta chain was expressed in Escherichia coli to study the functions of fibrinogen associated with this subunit. Recombinant B beta chains were expressed at 100 ng/mL in an IPTG- dependent manner. A first cistron sequence, inserted into the expression vector 5′ to the B beta chain cDNA, was required to express the protein. Recombinant B beta chains were expressed within five minutes after induction with IPTG and were soluble in physiologic buffers. The recombinant B beta chains migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) at a rate identical to B beta chains from fibrinogen treated with N-glycanase. Recombinant B beta chains were cleaved by thrombin, as demonstrated by the loss of cross-reactivity with a monoclonal antibody (MoAb) specific for the undigested B beta 1–42 fragment. The levels of expression of the B beta chain were much lower than those reported previously for the gamma chain of fibrinogen expressed in a similar vector in E coli. However, these levels are sufficient to allow further characterization of this fibrinogen subunit.


1996 ◽  
Vol 38 (6) ◽  
pp. 401-406 ◽  
Author(s):  
Yano Tomomasa ◽  
Cleide Ferreira Catani ◽  
Michiko Arita ◽  
Takeshi Honda ◽  
Toshio Miwatani

The mannose-resistant hemagglutinating factor (HAF) was extracted and purified from a diffuse adherent Escherichia coli (DAEC) strain belonging to the classic enteropathogenic E. coli (EPEC) serotype (0128). The molecular weight of HAF was estimated to be 18 KDa by SDS-PAGE and 66 KDa by Sephadex G100, suggesting that the native form of HAF consists of 3-4 monomeric HAF. Gold immunolabeling with specific HAF antiserum revealed that the HAF is not a rigid structure like fimbriae on the bacterial surface. The immunofluorescence test using purified HAF on HeLa cells, in addition to the fact that the HAF is distributed among serotypes of EPEC, suggests that HAF is a possible adhesive factor of DAEC strains


2003 ◽  
Vol 7 (5) ◽  
pp. 294-300 ◽  
Author(s):  
D. Turhani ◽  
C. Item ◽  
D. Thurnher ◽  
D. Kapral ◽  
B. Cvikl ◽  
...  
Keyword(s):  
Rt Pcr ◽  

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