Cloning and Expression of Fasciola gigantica Cathepsin-B Recombinant Proteins

Author(s):  
O. K. Raina ◽  
Andleeb Aftab ◽  
Savita Bisen ◽  
Rohit Lall ◽  
Shobha Yadav ◽  
...  

Fasciola gigantica cathepsin (cysteine) proteases are potential diagnostic antigens for animal and human fasciolosis. These include cathepsin-L proteases that have been exploited in the diagnosis of animal fasciolosis. However, no scientific data on the diagnostic potential of F. gigantica cathepsin B proteases is available. Therefore, three recombinant antigens of F. gigantica viz. cathepsin (cat) B-1, cat B-2 and cat B-3 were expressed in prokaryotic expression system. The recombinant antigens were purified under denaturing conditions by Nickel affinity chromatography and an optimal level of the recombinant proteins was obtained. These recombinant proteins will further be evaluated for their potential in the early prepatent diagnosis of F. gigantica infection in domestic ruminants.

2014 ◽  
Vol 185 ◽  
pp. S70
Author(s):  
Boguslaw Lupa ◽  
Krzysztof Stawujak ◽  
Igor Rozanski ◽  
Justyna Stec-Niemczyk

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Fei Du ◽  
Yun-Qi Liu ◽  
Ying-Shuang Xu ◽  
Zi-Jia Li ◽  
Yu-Zhou Wang ◽  
...  

AbstractEscherichia coli is the most widely used bacterium in prokaryotic expression system for the production of recombinant proteins. In BL21 (DE3), the gene encoding the T7 RNA polymerase (T7 RNAP) is under control of the strong lacUV5 promoter (PlacUV5), which is leakier and more active than wild-type lac promoter (PlacWT) under certain growth conditions. These characteristics are not advantageous for the production of those recombinant proteins with toxic or growth-burdened. On the one hand, leakage expression of T7 RNAP leads to rapid production of target proteins under non-inducing period, which sucks resources away from cellular growth. Moreover, in non-inducing or inducing period, high expression of T7 RNAP production leads to the high-production of hard-to-express proteins, which may all lead to loss of the expression plasmid or the occurrence of mutations in the expressed gene. Therefore, more BL21 (DE3)-derived variant strains with rigorous expression and different expression level of T7 RNAP should be developed. Hence, we replaced PlacUV5 with other inducible promoters respectively, including arabinose promoter (ParaBAD), rhamnose promoter (PrhaBAD), tetracycline promoter (Ptet), in order to optimize the production of recombinant protein by regulating the transcription level and the leakage level of T7 RNAP. Compared with BL21 (DE3), the constructed engineered strains had higher sensitivity to inducers, among which rhamnose and tetracycline promoters had the lowest leakage ability. In the production of glucose dehydrogenase (GDH), a protein that causes host autolysis, the engineered strain BL21 (DE3::ara) exhibited higher biomass, cell survival rate and foreign protein expression level than that of BL21 (DE3). In addition, these engineered strains had been successfully applied to improve the production of membrane proteins, including E. coli cytosine transporter protein (CodB), the E. coli membrane protein insertase/foldase (YidC), and the E. coli F-ATPase subunit b (Ecb). The engineered strains constructed in this paper provided more host choices for the production of recombinant proteins.


2009 ◽  
Vol 16 (4) ◽  
pp. 510-514 ◽  
Author(s):  
Lucyna Holec-Gąsior ◽  
Józef Kur ◽  
Elżbieta Hiszczyńska-Sawicka

ABSTRACT A goal of the current study was to evaluate serological applications of Toxoplasma gondii GRA2 and rhoptry protein 1 (ROP1) antigens. Soluble recombinant GRA2 and ROP1 antigens as fusion proteins containing six histidyl residues at the N and C terminals were obtained using an Escherichia coli expression system. Purification by one-step metal affinity chromatography allowed recovery of milligram amounts of pure recombinant proteins per liter of culture. The usefulness of these antigens for diagnosis of human infections was tested on 167 serum samples obtained during routine diagnostic tests. A panel of 37 serum samples from patients with acute toxoplasmosis was compared to a panel of 90 serum samples from individuals with past infection. The results indicated that both GRA2 and ROP1 recombinant antigens detected antibodies more frequently in samples from individuals with acute infections (100% and 94.6%, respectively) than in samples from individuals with chronic infections (22.5% and 15.5%, respectively). These results suggest that immunoglobulin G antibodies against GRA2 and ROP1 antigens are produced during the acute stage of toxoplasmosis but are uncommon in the chronic phase of the infection. Hence, these recombinant proteins can be used as specific molecular markers to differentiate between acute and chronic infections.


1999 ◽  
Vol 340 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Victor J. CHAN ◽  
Paul M. SELZER ◽  
James H. McKERROW ◽  
Judy A. SAKANARI

The mature form of the cathepsin B-like protease of Leishmania major (LmajcatB) is a 243 amino acid protein belonging to the papain family of cysteine proteases and is 54% identical to human-liver cathepsin B. Despite the high identity and structural similarity with cathepsin B, LmajcatB does not readily hydrolyse benzyloxycarbonyl-Arg-Arg-7-amino-4-methyl coumarin (Z-Arg-Arg-AMC), which is cleaved by cathepsin B enzymes. It does, however, hydrolyse Z-Phe-Arg-AMC, a substrate typically cleaved by cathepsin L and B enzymes. Based upon computer generated protein models of LmajcatB and mammalian cathepsin B, it was predicted that this variation in substrate specificity was attributed to Gly234 at the S2 subsite of LmajcatB, which forms a larger, more hydrophobic pocket compared with mammalian cathepsin B. To test this hypothesis, recombinant LmajcatB was expressed in the Pichia pastoris yeast expression system. The quality of the recombinant enzyme was confirmed by kinetic characterization, N-terminal sequencing, and Western blot analysis. Alteration of Gly234 to Glu, which is found at the corresponding site in mammalian cathepsin B, increased recombinant LmajcatB (rLmajcatB) activity toward Z-Arg-Arg-AMC 8-fold over the wild-type recombinant enzyme (kcat/Km = 3740±413 M-1·s-1 versus 472±72.4 M-1·s-1). The results of inhibition assays of rLmajcatB with an inhibitor of cathepsin L enzymes, K11002 (morpholine urea-Phe-homoPhe-vinylsulphonylphenyl, kinact/Ki = 208200±36000 M-1·s-1), and a cathepsin B specific inhibitor, CA074 [N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-ʟ-isoleucyl-L-proline, kinact/Ki = 199200±32900 M-1·s-1], support the findings that this protozoan protease has the P2 specificity of cathepsin L-like enzymes while retaining structural homology to mammalian cathepsin B.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Harisankar Singha ◽  
Praveen Malik ◽  
Sachin K. Goyal ◽  
Sandip K. Khurana ◽  
Chiranjay Mukhopadhyay ◽  
...  

Objective. To express truncated TssB protein ofBurkholderia malleiand to evaluate its diagnostic efficacy for serological detection of glanders among equines.Materials and Methods. In an attempt to develop recombinant protein based enzyme-linked immunosorbent assay (ELISA), N-terminal 200 amino acid sequences ofB. malleiTssB protein—a type 6 secretory effector protein—were expressed in prokaryotic expression system. Diagnostic potential of recombinant TssB protein was evaluated in indirect ELISA using a panel of glanders positive (n=49), negative (n=30), and field serum samples (n=1811). Cross-reactivity of the assay was assessed with equine disease control serum and human melioidosis positive serum.Results. In comparison to CFT, diagnostic sensitivity and specificity of ELISA were 99.7% and 100%, respectively.Conclusions. The indirect ELISA method using the truncated TssB offered safer and more rapid and efficient means of serodiagnosis of glanders in equines. These data highlight the use of TssB as potential diagnostic antigen for serological diagnosis of glanders.


2021 ◽  
Vol 7 (12) ◽  
pp. 999
Author(s):  
Manisha Shukla ◽  
Pankaj Chandley ◽  
Harsimran Kaur ◽  
Anup K. Ghosh ◽  
Shivaprakash M. Rudramurthy ◽  
...  

Systemic candidiasis is the fourth most common bloodstream infection in ICU patients worldwide. Although C. albicans is a predominant species causing systemic candidiasis, infections caused by non-albicans Candida (NAC) species are increasingly becoming more prevalent globally along with the emergence of drug resistance. The diagnosis of systemic candidiasis is difficult due to the absence of significant clinical symptoms in patients. We investigated the diagnostic potential of recombinant secreted aspartyl proteinase 2 (rSap2) from C. parapsilosis for the detection of Candida infection. The rSap2 protein was successfully cloned, expressed and purified using Ni-NTA chromatography under denaturing conditions using an E. coli-based prokaryotic expression system, and refolded using a multi-step dialysis procedure. Structural analysis by CD and FTIR spectroscopy revealed the refolded protein to be in its near native conformation. Immunogenicity analysis demonstrated the rSap2 protein to be highly immunogenic as evident from significantly high titers of Sap2-specific antibodies in antigen immunized Balb/c mice, compared to sham-immunized controls. The diagnostic potential of rSap2 protein was evaluated using immunoblotting and ELISA assays using proven candidiasis patient serum and controls. Immunoblotting results indicate that reactivity to rSap2 was specific to candidiasis patient sera with no cross reactivity observed in healthy controls. Increased levels of anti-Sap2-specific Ig, IgG and IgM antibodies were observed in candidiasis patients compared to controls and was similar in sensitivity obtained when whole Candida was used as coating antigen. In summary, the rSap2 protein from C. parapsilosis has the potential to be used in the diagnosis of systemic candidiasis, providing a rapid, convenient, accurate and cost-effective strategy.


2021 ◽  
Author(s):  
Ali Iftikhar

Abstract BackgroundOptimization of conditions for the recombinant production of proteins in a prokaryotic expression system is essential as the recombinant proteins impose a metabolic burden on cell's growth leading to low protein yield and low protein expression resulting from cell death.Main textThe concentration of media components is optimized to accommodate for depleted nutrients due to foreign protein expression. The temperature is optimized to reduce proteolytic degradation and accumulation of protein as inclusion bodies in Escherichia coli. The concentration of inducer and time of induction for high protein yield is also optimized. These optimization conditions depend on the promoter under which the gene of interest is present and the characteristics of the target protein.ConclusionIn the past few years, many optimization conditions for the production of recombinant proteins in Escherichia coli have been studied. These conditions depend mainly upon the promoter used to produce protein and the type of protein produced. Optimizing the expression parameters of protein produced in Escherichia coli ensures maximum yield of the desired protein.


2000 ◽  
Vol 7 (4) ◽  
pp. 600-606 ◽  
Author(s):  
Renee Lay Hong Lim ◽  
Li Kiang Tan ◽  
Wai Fun Lau ◽  
Maxey Ching Ming ◽  
Chung ◽  
...  

ABSTRACT Four immunoreactive proteins, B.4, B.6, B.10, and B.M, with molecular weights ranging from 16,000 to 58,000, were observed from immunoblots of Mycobacterium tuberculosis total lysates screened with sera from individuals with active tuberculosis. These proteins were identified from microsequence analyses, and genes of proteins with the highest homology were PCR amplified and cloned into the pQE30 vector for expression studies. In addition, a 37.5-kDa protein, designated C17, was identified from a phage expression library of M. tuberculosis genomic DNA. Preliminary immunoblot assays indicated that these five resultant recombinant proteins could detect antibodies in individuals with active pulmonary and extrapulmonary tuberculosis. The overall ranges of sensitivities, specificities, positive predictive values, and negative predictive values for the recombinant antigens were 20 to 58, 88 to 100, 69 to 100, and 56 to 71%, respectively. The B.6 antigen showed preferential reactivity to antibodies in pulmonary compared to nonpulmonary tuberculosis serum specimens. All of these recombinant antigens demonstrated potential for serodiagnosis of tuberculosis.


Author(s):  
Rafid A. Abdulkareem

The main goal of the current study was cloning and expression of the human insulin gene in Pichia pastoris expression system, using genetic engineering techniques and its treatment application. Total RNA was purified from fresh normal human pancreatic tissue. RNA of good quality was chosen to obtain a first single strand cDNA. Human preproinsulin gene was amplified from cDNA strand, by using two sets of specific primers contain EcoR1 and Notl restriction sites. The amplified preproinsulin gene fragment was double digested with EcoRI and Not 1 restriction enzymes, then inserted into pPIC9K expression vector. The new pPIC9K-hpi constructive expression vector was transformed by the heat-shock method into the E.coli DH5α competent cells. pPic9k –hpi, which was propagated in the positive transformant E. coli cells, was isolated from cells and then linearised by restriction enzyme SalI, then transformed into Pichia pastoris GS115 using electroporation method. Genomic DNA of His+ transformants cell was extracted and used as a template for PCR analysis. The results showed, that the pPic9k – hpi was successfully integrated into the P. pastoris genome, for selected His+ transformants clones on the anticipated band at 330 bp, which is corresponded to the theoretical molecular size of the human insulin gene. To follow the insulin expression in transformans, Tricine–SDS gel electrophoresis and Western blot analysis were conducted. The results showed a successful expression of recombinant protein was detected by the presence of a single major band with about (5.8 KDa) on the gel. These bands correspond well with the size of human insulin with the theoretical molecular weight (5.8 KDa).


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