scholarly journals Purification of p24 protein expressed in Bacillus subtilis and evaluation of its immunogenicity in mice

Author(s):  
Tuom Thi Tinh Truong ◽  
Trang Thi Phuong Phan ◽  
Hoang Duc Nguyen

p24 protein is a component of the HIV particle capsid. It plays an essential role in HIV to infect into the host cell and in the cycle life of virus. Therefore, this protein can be used in the orientative study “to create and produce HIV’s vaccine”. This study created the new Bacillus subtilis strain which expressed p24 protein. B. subtilis a safety and non-toxic bacteria strain for humans and animals, has system expression to allow over expression recombinant protein up to 10-30 % of total proteins. Plasmid pHT1537 was cloned successfully, containing lysSN-6his-gagp24 gene to encode p24 protein fused with LysSN protein and to allow the expression of p24 protein in B. subtilis by IPTG inducer. The target protein in the cell was cheked by SDS-PAGE. The p24 fused protein was parified from His Trap column which contained Ni2+. Evaluation of the ability to produce antibody against p24 protein in mice by ELISA and Western blot was caried out.

2020 ◽  
Vol 18 (2) ◽  
pp. 363-372
Author(s):  
Nguyen Tien Cuong ◽  
Nguyen Thi Hien Trang ◽  
Nguyen Thi Thao ◽  
Le Thanh Hoang ◽  
Nguyen Sy Le Thanh ◽  
...  

Maltooligosyltrehalose trehalohydrolase (MTHase) is an industrial enzyme for the production of trehalose. A DNA fragment of 1680 bp encoding for MTHase was cloned from Sulfobolus solfataricus DSM 1616 then fused with promoter acoA-amyE already amplified from pMSE3 vector by PCR to generate an expression cassette acoMTH. Afterward the cassette was inserted into pAC7 vector for expression of the gene in Bacillus subtilis WB800 – a conventional expression system. Gene MTH was inserted into the genome of B. subtilis WB800 by cross-exchange event of pAC7 vector with the host genome for expression of high quality and high quantity of extracellular recombinant protein. By crossing-exchange event at 3’amyE-5’amyE, the expressional cassette was integrated into B. subtilis WB800 genome. The expressional cassette was integrated into B. subtilis WB800 genome replacing 3’amyE-5’amyE, hindering the native amylase activity of the host. Expression of expected protein was confirmed by electrophoresis SDS-PAGE. From our results, it indicates that gene MTH was expressed successfully in B. subtilis WB800. After 0.5% acetoin induction for 48 h, the data showed that the protein with a molecular mass of ~64 kDa on SDS-PAGE was expressed. The level of recombinant protein in WBpAacoMTH was increased and reached 2.5%, 15.2% and 21.95%, respectively comparing with native B. subtilis WB800.


2016 ◽  
Vol 78 (11-3) ◽  
Author(s):  
Tan Wee Yee ◽  
Darah Ibrahim ◽  
Khoo Boon Yin ◽  
Chew Ai Lan

D6 and DARC are decoy chemokine binding receptors. They had been studied extensively in recent years for their role in breast cancer studies. The purpose of this study was to improve some critical steps in Western Blot in order to detect and identify recombinant D6 and DARC which has been expressed intracellularly by Pichia-GS115. Total proteins of Pichia-GS115 were obtained by breaking the yeast cells using acid-washed glass beads. Then, the lysates were treated with treatment buffer before electrophoresed on SDS-polyacrylamide gel. Western Blot was carried out after SDS PAGE to detect and identify the presence of recombinant D6 and DARC. Several parameters of Western Blot were studied and improved to enhance the specificity of results obtained. It was found that blocking of nitrocellulose membrane with 3% (w/v) skimmed milk at room temperature for 1 hour, incubation of primary antibody at the dilution of 1: 300 at room temperature for 16 hours and incubation of secondary antibody at the dilution of 1: 1000 at room temperature for 1 hour were able to enhance the sensitivity and specificity of Western Blot results. With the aid of prestained protein ladder as a marker, recombinant D6 and also DARC were shown as clear and precise bands at the range of molecular weight of 50-60 kDa on developed films using ECL substrate. The film exposure time was found to be 5 minutes for D6 and 10 minutes for DARC. As a result, the studies showed that improved Western Blot condition detected and identified the presence of recombinant D6 and DARC in the cell pellets of Pichia-GS115


2020 ◽  
Vol 14 (12) ◽  
pp. 1442-1447
Author(s):  
Oswaldo M Torres-Chable ◽  
Ligia G Brito-Argaez ◽  
Ignacio R Islas-Flores ◽  
Claudia V Zaragoza-Vera ◽  
Maritza Zaragoza-Vera ◽  
...  

Introduction: Dirofilaria immitis is a nematode that affects human health in several countries of the world. This study was conducted to examine whether serum samples from the owners of microfilaremic dogs present immunoreactivity to parasite proteins. Methodology: Eight serum samples from the owners of microfilaremic dogs were examined. Total proteins were extracted from adult worms and 12% SDS-PAGE was performed. The gel was electroblotted to a nitrocellulose membrane, and a Western blot (WB) was performed. Reactive bands of 22, 33, 39, 49, and 63 kDa in WB were excised from the gel and analyzed by mass spectrometry (MS). Results: The MS results showed the presence of 10 different proteins of D. immitis recognized by the human serum samples. Conclusions: These results indicate that in endemic areas of D. immitis, owners of infected dogs recognize specific proteins of the parasite, suggesting a possible infection.


2018 ◽  
Vol 4 (2) ◽  
pp. 98-106
Author(s):  
Muktiningsih - Nurjayadi ◽  
Izzatul Ilma Chairinnisa ◽  
Geta Putri Mentari ◽  
Dudi Hardianto ◽  
Asri Sulfianti ◽  
...  

Recombinant protein Fim-C S.typhi is a potential protein that can be used as an alternative typhoid vaccine and produced on a large scale. However, before entering into a large-scale stage, laboratory optimum data on the factors that affect the production process of Fim-C Salmonella typhi proteins are required. This study aims to obtain information regarding the effect of host cell number E.coli BL21 (DE3) pLysS and overexpression time on production of recombinant protein Fim-C Salmonella typhi as the basis for developing candidate of typhoid vaccine. The optimization process of overexpression was done by adding 0.5 mM IPTG (Isopropyl-β-D-thiogalactopyranoside) inducer into bacterial cultures of 2%, 4%, and 6% with 4, 5, and 6 hours over expression. The measurement of the concentration of Fim-C recombinant protein extracted samples were done by a spectrophotometric method used BCA Kit Assay Thermo ScientificTM with wavelength 590nm. The characterization of those protein extracts was performed using SDS-PAGE method. The results from the study concluded that the number of 4% E.coli bacterial cells and four-hour overexpression time are the optimum condition of Fim- C Salmonella typhi characterized by the presence of high-intensity bands at ± 31 kDa.  


2011 ◽  
Vol 14 (3) ◽  
pp. 73-79
Author(s):  
Duy Long Duong ◽  
Duc Van Luong ◽  
Hieu Thi Phuong Nguyen ◽  
Hoa Thanh Tran ◽  
Thao Thi Phuong Dang ◽  
...  

In this study, we report results on the expression and purification of recombinant T4 DNA ligase. Plasmid pET16b-T4Dnl contains the gp30 gene which encodes for T4 DNA ligase. The target protein is fused with 10xHis tag to facilitate the purification and recovery. pET16b-T4Dnl was transformed into E. coli BL21(DE3) and then induced the expression of 10xHis-T4Dnl by IPTG. The recombinant protein was purified by Ni-NTA chromatography and confirmed by SDS-PAGE and Western blot. The activity of purified protein was tested by joining DNA λ/HindIII.


1989 ◽  
Vol 61 (03) ◽  
pp. 437-441 ◽  
Author(s):  
Cindra Condra ◽  
Elka Nutt ◽  
Christopher J Petroski ◽  
Ellen Simpson ◽  
P A Friedman ◽  
...  

SummaryThe present work reports the discovery and charactenzation of an anticoagulant protein in the salivary gland of the giant bloodsucking leech, H. ghilianii, which is a specific and potent inhibitor of coagulation factor Xa. The inhibitor, purified to homogeneity, displayed subnanomolar inhibition of bovine factor Xa and had a molecular weight of approximately 15,000 as deduced by denaturing SDS-PAGE. The amino acid sequence of the first 43 residues of the H. ghilianii derived inhibitor displayed a striking homology to antistasin, the recently described subnanomolar inhibitor of factor Xa isolated from the Mexican leech, H. officinalis. Antisera prepared to antistasin cross-reacted with the H. ghilianii protein in Western Blot analysis. These data indicate that the giant Amazonian leech, H. ghilianii, and the smaller Mexican leech, H. officinalrs, have similar proteins which disrupt the normal hemostatic clotting mechanisms in their mammalian host’s blood.


1991 ◽  
Vol 65 (04) ◽  
pp. 382-388 ◽  
Author(s):  
Dulce Veloso ◽  
Robert W Colman

SummaryPrekallikrein (PK), a zymogen of the contact system, and its activation products, kallikrein (KAL), KAl-inhibitor complexes and fragments containing KAL epitope(s) have been detected in human plasma by immunoblotting with a monoclonal anti-human plasma PK antibody, MAb 13G1L. Detection of antigen-MAb 13G11 complexes with peroxidase-conjugated anti-IgG showed that the two variants of PK (85- and 88-kDa) are the only major antigen species in normal, non-activated plasma. Upon plasma activation with kaolin, the intensity of the PK bands decreased with formation of complexes of KAL with CL inhibitor (C1 INH) and α2-rrtzcroglobulin (α2M) identical to those formed by the purified proteins. Immunoblots of normal plasma showed good correlation between the PK detected and the amount of plasma assayed. Increasing amounts of KAL incubated with a constant volume of PK-deficient plasma showed increasing amounts of KAL and of KAL-C1 INH and KAL-α2M complexes. Complexes of KALantithrombin III (ATIII) and the ratio of KALα2M/ KAL-CL INH were higher in activated CL INH-deficient plasmas than in activated normal plasmas. Protein resolution by 3-12% gradient SDS-PAGE and epitope detection with [125I]MAb 13G11 showed four KALα2M species and a 45-kDa fragment(s) in both surface-activated normal plasma and complexes formed by purified KAL and α2M. Immunoblots of activated plasma also showed bands at the position of KALCL INH and KALATIII complexes. When α1-antitrypsin Pittsburgh (cα1-AT, Pitts) was added to plasma before activation, KAL-α1-ALPitts was the main complex. The non-activated normal plasma revealed only an overloaded PK band. This is the first report of an antibody that recognizes KAL epitope(s) in KAL-α2M, KALATIII and KALa1-α1Pitts complexes and in the 45-kDa fragment(s). Therefore, MAb 13G11 should be useful for studying the structure of these complexes as well as the mechanism of complex formation. In addition, immunoblotting with MAb 13G11 would allow detection of KAl-inhibitor complexes in patient plasmas as indicators of activation of the contact system.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 28.1-29
Author(s):  
A. Kerstein-Staehle ◽  
C. Alarcin ◽  
J. Luo ◽  
G. Riemekasten ◽  
P. Lamprecht ◽  
...  

Background:The immunomodulatory cytokine IL-16 is increased in several inflammatory and autoimmune diseases1. IL-16 recruits and activates CD4+ immune cells such as T cells, dendritic cells, or monocytes. IL-16 is produced by various immune and non-immune cells, but synthesis and storage of IL-16 is regulated differentially depending on the cell type and stimulation. For its biological activity, IL-16 cleavage by caspase-3 is required1. Necrotizing granulomatous inflammation is a hallmark of granulomatosis with polyangiitis (GPA) with neutrophil dysregulation as a central driver of chronic inflammation and autoimmunity2. Earlier studies showed a correlation between increased serum IL-16 and disease parameters in AAV, including GPA3, but functional evidence for a direct link between IL-16 and neutrophils in granulomatous inflammation is missing so far.Objectives:In this study we aim to identify a functional link between increased IL-16, neutrophils, and the autoantigen proteinase 3 (PR3) with regard to chronic inflammation and autoimmunity in GPA.Methods:IL-16 was measured in sera of GPA patients (n = 40) and healthy controls (HC, n = 50) by ELISA and correlated with clinical features, such as disease activity (BVAS), creatinine, GFR, VDI and PR3-ANCA status. IL-16 protein expression was analyzed in peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) from GPA patients and HC (n = 5, each) by SDS-PAGE and western blot. Binding affinity of recombinant pro-IL-16 to native human PR3 was assessed by microscale thermophoresis. Cleavage of pro-IL-16 by active human PR3 was performed at various time points at 37°C. Cleavage products were analyzed by SDS-PAGE and western blot.Results:Circulating IL-16 was significantly increased in GPA patients compared to HC. Elevated IL-16 positively correlated with BVAS, creatinine, VDI and PR3-ANCA status and negatively correlated with GFR. In PMBC and PMN from GPA and HC we identified different expression patters of precursor and active forms of IL-16. In healthy PBMC we found high amounts of precursor (80kD), pro-IL-16 (55kD) and active IL-16 (17kD). In contrast, PBMC from GPA patients had lower amounts of pro-IL-16 and no active IL-16, indicating activation and secretion of IL-16 due to inflammatory stimulation, as shown earlier5. In GPA PMN we detected no precursor IL-16, but pro-IL-16 and its active form, in contrast to very low amounts of all IL-16 forms in healthy PMN. Processing and release of IL-16 in neutrophils has been linked to apoptosis and secondary necrosis5. By interaction studies we demonstrated direct binding of pro-IL-16 to PR3 with a Kd of 10 nM. In a subsequent cleavage assay we confirmed IL-16 processing by PR3 in a time-dependent manner.Conclusion:Correlation of serum IL-16 with clinical features of GPA suggests that IL-16 is associated with markers of disease activity, tissue damage and autoreactivity. We showed that PBMC and PMN represent a source of IL-16 in GPA. By the identification of PR3 as an additional IL-16-activating enzyme we could demonstrate a potential link between excessive PR3 expression, cell death and IL-16-dependent mechanisms, contributing to chronic granulomatous inflammation and autoimmunity in GPA.References:[1]Glass, W. G. et al. Not-so-sweet sixteen: The role of IL-16 in infectious and immune-mediated inflammatory diseases. J. Interf. Cytokine Res. 26, 511–520 (2006).[2]Millet, A. et al. Proteinase 3 on apoptotic cells disrupts immune silencing in autoimmune vasculitis. J. Clin. Invest. 125, 4107–4121 (2015).[3]Yoon, T. et al. Serum interleukin-16 significantly correlates with the Vasculitis Damage Index in antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Res. Ther. 22, 1–6 (2020).[4]Elssner, A. et al. IL-16 Is Constitutively Present in Peripheral Blood Monocytes and Spontaneously Released During Apoptosis. J. Immunol. 172, 7721–7725 (2004).[5]Roth, S. et al. Secondary necrotic neutrophils release interleukin-16C and macrophage migration inhibitory factor from stores in the cytosol. Cell Death Discov. 1, 15056 (2015).Disclosure of Interests:None declared


2019 ◽  
Vol 14 (1) ◽  
pp. 528-536
Author(s):  
Li-Qiong Huang ◽  
Bo Zheng ◽  
Yi He

AbstractTumor necrosis factor (TNF)-α-induced protein-8-like 2, or TIPE2, is a newly found immune negative regulatory molecule. This study further investigated the role of TIPE2 on proliferation and invasion of cervical squamous cancer cells. Expression of TIPE2 was compared in cervical squamous cancer tissues and adjacent normal tissues by Western blot and immunohistochemistry (IHC). Cervical squamous cancer cell lines, SiHa and C33A, were transfected with recombinant plasmid encoding TIPE2 and tested for cytologic characteristics. The impact of TIPE2 on phosphorylation of extracellular signal-regulated kinase (Erk) signaling pathway was also tested by Western blot analysis of key factors. TIPE2 expression was higher in cervical cancer tissues than that in normal tissue. IHC score of tumor tissue was negatively associated with lymphatic metastasis. Over expression of TIPE2 effectively inhibited the proliferation of cervical cancer cells. Wound healing and transwell assay showed that over expression of TIPE2 suppressed cell migration and invasion in vitro. Meanwhile, phosphorylation of Erk1/2 and upstream mitogen-activated protein kinase kinase (MEK) 1/2 was reduced by TIPE2. TIPE2 is negatively related with development of cervical squamous cancer. TIPE2 is an inhibitory factor of proliferation and invasion of cervical squamous cancer cells, probably through inhibiting Erk signaling pathway.


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