Displaying publications 61 - 80 of 366 in total

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  1. Fulltext Evaluation of recombinant Plasmodium knowlesi merozoite surface protein-1(33) for detection of human malaria
    Cheong FW, Lau YL, Fong MY, Mahmud R
    Am J Trop Med Hyg, 2013 May;88(5):835-40.
    PMID: 23509118 DOI: 10.4269/ajtmh.12-0250
    Plasmodium knowlesi is now known as the fifth Plasmodium species that can cause human malaria. The Plasmodium merozoite surface protein (MSP) has been reported to be potential target for vaccination and diagnosis of malaria. MSP-1(33) has been shown to be immunogenic and its T cell epitopes could mediate cellular immune protection. However, limited studies have focused on P. knowlesi MSP-133. In this study, an approximately 28-kDa recombinant P. knowlesi MSP-1(33) (pkMSP-1(33)) was expressed by using an Escherichia coli system. The purified pkMSP-1(33) reacted with serum samples of patients infected with P. knowlesi (31 of 31, 100%) and non-P. knowlesi malaria (27 of 28, 96.43%) by Western blotting. The pkMSP-1(33) also reacted with P. knowlesi (25 of 31, 80.65%) and non-P. knowlesi malaria sera (20 of 28, 71.43%) in an enzyme-linked immunosorbent assay (ELISA). Most of the non-malarial infection (49 of 52 in by Western blotting and 46 of 52 in the ELISA) and healthy donor serum samples (65 of 65 by Western blotting and ELISA) did not react with recombinant pkMSP-1(33).
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/immunology; Recombinant Proteins/isolation & purification
  2. Fulltext Characterization of the highly active polyhydroxyalkanoate synthase of Chromobacterium sp. strain USM2
    Bhubalan K, Chuah JA, Shozui F, Brigham CJ, Taguchi S, Sinskey AJ, et al.
    Appl Environ Microbiol, 2011 May;77(9):2926-33.
    PMID: 21398494 DOI: 10.1128/AEM.01997-10
    The synthesis of bacterial polyhydroxyalkanoates (PHA) is very much dependent on the expression and activity of a key enzyme, PHA synthase (PhaC). Many efforts are being pursued to enhance the activity and broaden the substrate specificity of PhaC. Here, we report the identification of a highly active wild-type PhaC belonging to the recently isolated Chromobacterium sp. USM2 (PhaC(Cs)). PhaC(Cs) showed the ability to utilize 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx) monomers in PHA biosynthesis. An in vitro assay of recombinant PhaC(Cs) expressed in Escherichia coli showed that its polymerization of 3-hydroxybutyryl-coenzyme A activity was nearly 8-fold higher (2,462 ± 80 U/g) than that of the synthase from the model strain C. necator (307 ± 24 U/g). Specific activity using a Strep2-tagged, purified PhaC(Cs) was 238 ± 98 U/mg, almost 5-fold higher than findings of previous studies using purified PhaC from C. necator. Efficient poly(3-hydroxybutyrate) [P(3HB)] accumulation in Escherichia coli expressing PhaC(Cs) of up to 76 ± 2 weight percent was observed within 24 h of cultivation. To date, this is the highest activity reported for a purified PHA synthase. PhaC(Cs) is a naturally occurring, highly active PHA synthase with superior polymerizing ability.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism; Recombinant Proteins/chemistry
  3. Fulltext Recombinant dense granular protein (GRA5) for detection of human toxoplasmosis by Western blot
    Ching XT, Lau YL, Fong MY, Nissapatorn V, Andiappan H
    Biomed Res Int, 2014;2014:690529.
    PMID: 24987700 DOI: 10.1155/2014/690529
    Toxoplasma gondii infects all warm-blooded animals, including humans, causing serious public health problems and great economic loss for the food industry. Commonly used serological tests require costly and hazardous preparation of whole Toxoplasma lysate antigens from tachyzoites. Here, we have evaluated an alternative method for antigen production, which involved a prokaryotic expression system. Specifically, we expressed T. gondii dense granular protein-5 (GRA5) in Escherichia coli and isolated it by affinity purification. The serodiagnostic potential of the purified recombinant GRA5 (rGRA5) was tested through Western blot analysis against 212 human patient serum samples. We found that rGRA5 protein was 100% specific for analysis of toxoplasmosis-negative human sera. Also, rGRA5 was able to detect acute and chronic T. gondii infections (sensitivities of 46.8% and 61.2%, resp.).
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/chemistry
  4. Principles and application of antibody libraries for infectious diseases
    Lim BN, Tye GJ, Choong YS, Ong EB, Ismail A, Lim TS
    Biotechnol Lett, 2014 Dec;36(12):2381-92.
    PMID: 25214212 DOI: 10.1007/s10529-014-1635-x
    Antibodies have been used efficiently for the treatment and diagnosis of many diseases. Recombinant antibody technology allows the generation of fully human antibodies. Phage display is the gold standard for the production of human antibodies in vitro. To generate monoclonal antibodies by phage display, the generation of antibody libraries is crucial. Antibody libraries are classified according to the source where the antibody gene sequences were obtained. The most useful library for infectious diseases is the immunized library. Immunized libraries would allow better and selective enrichment of antibodies against disease antigens. The antibodies generated from these libraries can be translated for both diagnostic and therapeutic applications. This review focuses on the generation of immunized antibody libraries and the potential applications of the antibodies derived from these libraries.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/therapeutic use
  5. Intracellular production of IFN-alpha 2b in Lactococcus lactis
    Bayat O, Baradaran A, Ariff A, Mohamad R, Rahim RA
    Biotechnol Lett, 2014 Mar;36(3):581-5.
    PMID: 24185903 DOI: 10.1007/s10529-013-1390-4
    Human interferon alpha (IFN-α) was expressed in two strains of Lactococcus lactis by aid of two promoters (P32 and Pnis) giving rise to two recombinant strains: MG:IFN and NZ:IFN, respectively. The expression of IFN was confirmed by ELISA and western blotting. Highest production was achieved using glucose for growth of both recombinant strains with nisin, used for induction of the recombinant strain with Pnis promoter, at 30 ng/ml. The optimum time for MG:IFN was 9 h and for NZ:IFN was 4.5 h. The highest productions by MG:IFN and NZ:IFN were 1.9 and 2.4 μg IFN/l, respectively. Both of the expressed IFNs showed bioactivities of 1.9 × 10(6) IU/mg that were acceptable for further clinical studies.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism
  6. Fulltext Expression and Characterization of Geobacillus stearothermophilus SR74 Recombinant α-Amylase in Pichia pastoris
    Gandhi S, Salleh AB, Rahman RN, Chor Leow T, Oslan SN
    Biomed Res Int, 2015;2015:529059.
    PMID: 26090417 DOI: 10.1155/2015/529059
    Geobacillus stearothermophilus SR74 is a locally isolated thermophilic bacteria producing thermostable and thermoactive α-amylase. Increased production and commercialization of thermostable α-amylase strongly warrant the need of a suitable expression system. In this study, the gene encoding the thermostable α-amylase in G. stearothermophilus SR74 was amplified, sequenced, and subcloned into P. pastoris GS115 strain under the control of a methanol inducible promoter, alcohol oxidase (AOX). Methanol induced recombinant expression and secretion of the protein resulted in high levels of extracellular amylase production. YPTM medium supplemented with methanol (1% v/v) was the best medium and once optimized, the maximum recombinant α-amylase SR74 achieved in shake flask was 28.6 U mL(-1) at 120 h after induction. The recombinant 59 kDa α-amylase SR74 was purified 1.9-fold using affinity chromatography with a product yield of 52.6% and a specific activity of 151.8 U mg(-1). The optimum pH of α-amylase SR74 was 7.0 and the enzyme was stable between pH 6.0-8.0. The purified enzyme was thermostable and thermoactive, exhibiting maximum activity at 65°C with a half-life (t₁/₂) of 88 min at 60°C. In conclusion, thermostable α-amylase SR74 from G. stearothermophilus SR74 would be beneficial for industrial applications, especially in liquefying saccrification.
    Matched MeSH terms: Recombinant Proteins/biosynthesis; Recombinant Proteins/genetics*
  7. Transactivator protein: An alternative for delivery of recombinant proteins for safer reprogramming of induced Pluripotent Stem Cell
    Nordin F, Ahmad RNR, Farzaneh F
    Virus Res, 2017 05 02;235:106-114.
    PMID: 28408207 DOI: 10.1016/j.virusres.2017.04.007
    Induced pluripotent stem cells (iPSC) are somatic cells reprogrammed to pluripotency by forced expression of pluripotency factors. These cells are shown to have the same pluripotent potential as embryonic stem cells (ESC) and considered as an alternative to the much controversial usage of ESC which involved human embryos. However, the traditional method in reprogramming cells into iPSC using genome-integrating retro- or lenti- viruses remains an obstacle for its application in clinical setting. Although numerous studies have been conducted for a safer DNA-based reprogramming, reprogramming of iPSC by genetic modifications may raise the possibility of malignant transformation and has been a major limitation for its usage in clinical applications. Therefore, there is a need for an alternative method to reprogram the cells without the use of gene editing and a much safer way to deliver transcription factors to induce pluripotency on target cells. Using protein transduction approach, a number of studies have demonstrated the generation of human iPSCs from human fibroblasts and mouse embryonic fibroblasts by direct delivery of reprogramming proteins. In this review, the definition and mechanism of HIV-TAT protein (a type of protein transduction domain) in delivering recombinant proteins, including the potential of protein-based delivery to induce iPSC were further discussed.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism*
  8. An effective extracellular protein secretion by an ABC transporter system in Escherichia coli: statistical modeling and optimization of cyclodextrin glucanotransferase secretory production
    Low KO, Mahadi NM, Rahim RA, Rabu A, Abu Bakar FD, Murad AM, et al.
    J Ind Microbiol Biotechnol, 2011 Sep;38(9):1587-97.
    PMID: 21336875 DOI: 10.1007/s10295-011-0949-0
    Direct transport of recombinant protein from cytosol to extracellular medium offers great advantages, such as high specific activity and a simple purification step. This work presents an investigation on the potential of an ABC (ATP-binding cassette) transporter system, the hemolysin transport system, for efficient protein secretion in Escherichia coli (E. coli). A higher secretory production of recombinant cyclodextrin glucanotransferase (CGTase) was achieved by a new plasmid design and subsequently by optimization of culture conditions via central composite design. An improvement of at least fourfold extracellular recombinant CGTase was obtained using the new plasmid design. The optimization process consisted of 20 experiments involving six star points and six replicates at the central point. The predicted optimum culture conditions for maximum recombinant CGTase secretion were found to be 25.76 μM IPTG, 1.0% (w/v) arabinose and 34.7°C post-induction temperature, with a predicted extracellular CGTase activity of 68.76 U/ml. Validation of the model gave an extracellular CGTase activity of 69.15 ± 0.71 U/ml, resulting in a 3.45-fold increase compared to the initial conditions. This corresponded to an extracellular CGTase yield of about 0.58 mg/l. We showed that a synergistic balance of transported protein and secretory pathway is important for efficient protein transport. In addition, we also demonstrated the first successful removal of the C-terminal secretion signal from the transported fusion protein by thrombin proteolytic cleavage.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism
  9. The potential correlation between patient-reported symptoms and the use of additional haemostatic medication for joint bleeding in haemophilia patients with inhibitors: a post hoc exploratory analysis of recombinant activated factor VII data from the ADEPT2 trial
    Lentz SR, Rangarajan S, Karim FA, Andersen PD, Arkhammar P, Rosu G, et al.
    Blood Coagul Fibrinolysis, 2017 Apr;28(3):224-229.
    PMID: 27427786 DOI: 10.1097/MBC.0000000000000584
    : Haemophilia treatment guidelines advocate early home-based treatment of acute bleeds. In the ADEPT2 trial, data were collected on the home treatment of bleeds with recombinant activated factor VII (rFVIIa) in haemophilia patients with inhibitors and self-reported bleeding-related symptoms. A total of 93% of all bleeds, and 91.5% of joint bleeds, were treated successfully with one to three doses of 90 μg/kg rFVIIa. However, some patients self-administered additional haemostatic medication (AHM) up to 48 h after the first rFVIIa treatment. The aim of this trial was to investigate the relationship between patient-reported symptoms, time to treatment initiation, and the use of AHM. A post hoc analysis was conducted on 177 joint bleeds and the patient-reported categorical symptoms of pain, swelling, mobility, tingling, and warmth, and the pain visual analogue scale (VAS) score. Analyses were descriptive and used logistic regression modelling. Complete symptom data were available for 141, 136, and 129 joint bleeds at 0 or 1, 3, and 6 h, respectively. Pain and pain VAS assessments were the best predictors of AHM use. Patients who self-administered AHM had higher mean pain VAS scores at each time point; both pain and pain VAS scores declined over time. Time to treatment initiation was an independent predictor for AHM use. Higher initial pain scores and longer time to treatment were the best predictors for administration of AHM. The observation that some patients chose to self-infuse in the face of declining levels of pain warrants further study to better understand the reasons behind patient decision-making.
    Matched MeSH terms: Recombinant Proteins/administration & dosage; Recombinant Proteins/therapeutic use
  10. Effect of different operating modes and biomass concentrations on the recovery of recombinant hepatitis B core antigen from thermal-treated unclarified Escherichia coli feedstock
    Ng MY, Tan WS, Abdullah N, Ling TC, Tey BT
    J Biotechnol, 2008 Nov 25;138(3-4):74-9.
    PMID: 18786579 DOI: 10.1016/j.jbiotec.2008.08.004
    Expanded bed adsorption chromatography (EBAC) is a single pass operation that has been used as primary capture step in various protein purifications. The most common problem in EBAC is often associated with successful formation of a stable fluidized bed during the absorption stage, which is critically dependent on parameters such as liquid velocity, bed height, particle (adsorbent) size and density as well as design of column and type of flow distributor. In this study, residence time distribution (RTD) test using acetone as non-binding tracer acetone was performed to evaluate liquid dispersion characteristics of the EBAC system. A high B(o) number was obtained indicating the liquid dispersion in the system employed is very minimal and the liquid flow within the bed was close to plug flow, which mimics a packed bed chromatography system. Evaluation on the effect of flow velocities and bed height on the performance of Streamline DEAE using feedstock containing heat-treated crude Escherichia coli homogenate of different biomass concentrations was carried out in this study. The advantages and disadvantages as well as the problems encountered during recovery of HBcAg with aforementioned parameters are also discussed in this paper.
    Matched MeSH terms: Recombinant Proteins/isolation & purification*; Recombinant Proteins/metabolism
  11. Stepwise optimization of recombinant protein production in Escherichia coli utilizing computational and experimental approaches
    Packiam KAR, Ramanan RN, Ooi CW, Krishnaswamy L, Tey BT
    Appl Microbiol Biotechnol, 2020 Apr;104(8):3253-3266.
    PMID: 32076772 DOI: 10.1007/s00253-020-10454-w
    Over the past few decades, Escherichia coli (E. coli) remains the most favorable host among the microbial cell factories for the production of soluble recombinant proteins. Recombinant protein production (RPP) via E. coli is optimized at the level of gene expression (expression level) and the process condition of fermentation (process level). Presently, the reported studies do not give a clear view on the selection of methods employed in the optimization of RPP. Here, we have reviewed various optimization methods and their preferences with respect to the factors at expression and process levels to achieve the optimal levels of soluble RPP. With a greater understanding of these optimization methods, we proposed a stepwise methodology linking the factors from both levels for optimizing the production of soluble recombinant protein in E. coli. The proposed methodology is further explained through five sets of examples demonstrating the optimization of RPP at both expression and process levels.Key Points• Stepwise methodology of optimizing recombinant protein production is proposed.• In silico tools can facilitate the optimization of gene- and protein-based factors.• Optimization of gene- and protein-based factors aids host-vector selection.• Statistical optimization is preferred for achieving optimal levels of process factors.
    Matched MeSH terms: Recombinant Proteins/biosynthesis*; Recombinant Proteins/genetics*
  12. Fulltext Production of recombinant human epidermal growth factor in Pichia pastoris
    Eissazadeh S, Moeini H, Dezfouli MG, Heidary S, Nelofer R, Abdullah MP
    Braz J Microbiol, 2017 Apr-Jun;48(2):286-293.
    PMID: 27998673 DOI: 10.1016/j.bjm.2016.10.017
    This study was carried out to express human epidermal growth factor (hEGF) in Pichia pastoris GS115. For this aim, the hEGF gene was cloned into the pPIC9K expression vector, and then integrated into P. pastoris by electroporation. ELISA-based assay showed that the amount of hEGF secreted into the medium can be affected by the fermentation conditions especially by culture medium, pH and temperature. The best medium for the optimal hEGF production was BMMY buffered at a pH range of 6.0 and 7.0. The highest amount of hEGF with an average yield of 2.27μg/mL was obtained through an induction of the culture with 0.5% (v/v) methanol for 60h. The artificial neural network (ANN) analysis revealed that changes in both pH and temperature significantly affected the hEGF production with the pH change had slightly higher impact on hEGF production than variations in the temperature.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/secretion*
  13. Biophysical characterization of a recombinant lipase KV1 from Acinetobacter haemolyticus in relation to pH and temperature
    Batumalaie K, Khalili E, Mahat NA, Huyop F, Wahab RA
    Biochimie, 2018 Sep;152:198-210.
    PMID: 30036604 DOI: 10.1016/j.biochi.2018.07.011
    Spectroscopic and calorimetric methods were employed to assess the stability and the folding aspect of a novel recombinant alkaline-stable lipase KV1 from Acinetobacter haemolyticus under varying pH and temperature. Data on far ultraviolet-circular dichroism of recombinant lipase KV1 under two alkaline conditions (pH 8.0 and 12.0) at 40 °C reveal strong negative ellipticities at 208, 217, 222 nm, implying its secondary structure belonging to a α + β class with 47.3 and 39.0% ellipticity, respectively. Results demonstrate that lipase KV1 adopts its most stable conformation at pH 8.0 and 40 °C. Conversely, the protein assumes a random coil structure at pH 4.0 and 80 °C, evident from a strong negative peak at ∼ 200 nm. This blue shift suggests a general decline in enzyme activity in conjunction with the partially or fully unfolded state that invariably exposed more hydrophobic surfaces of the lipase protein. The maximum emission at ∼335 nm for pH 8.0 and 40 °C indicates the adoption of a favorable protein conformation with a high number of buried tryptophan residues, reducing solvent exposure. Appearance of an intense Amide I absorption band at pH 8.0 corroborates an intact secondary structure. A lower enthalpy value for pH 4.0 over pH 8.0 and 12.0 in the differential scanning calorimetric data corroborates the stability of the lipase at alkaline conditions, while a low Km (0.68 ± 0.03 mM) for tributyrin verifies the high affinity of lipase KV1 for the substrate. The data, herein offer useful insights into future structure-based tunable catalytic activity of lipase KV1.
    Matched MeSH terms: Recombinant Proteins/metabolism; Recombinant Proteins/chemistry
  14. Strategies for humanizing glycosylation pathways and producing recombinant glycoproteins in microbial expression systems
    Khan AH, Noordin R
    Biotechnol Prog, 2019 03;35(2):e2752.
    PMID: 30457225 DOI: 10.1002/btpr.2752
    Homogeneously glycosylated proteins are essential for analyzing the structure of N-glycans, studying their consequences inside cells, and developing therapeutic glycoproteins. However, the isolation of glycoproteins with homogeneous glycans from human is difficult since glycoforms slightly differ from each other with respect to molecular weight and charge. Microbial expression systems have numerous benefits in expression technology and have gained great attention, because they are more adaptable to the biotechnology industry. While selecting an expression host, the glycosylation pattern must be taken into account, because glycosylation strongly depends on cellular production system and selected production clone. This review discussed the technological developments in glycoengineering of microbial expression systems for humanizing the glycosylation profile and highlighted the expression potential of Leishmania expression system. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2752, 2019.
    Matched MeSH terms: Recombinant Proteins/biosynthesis*; Recombinant Proteins/chemistry
  15. Clone, expression and plasminogen binding property of three fructose-1,6-bisphosphate aldolases from Clonorchis sinensis
    Li S, Lu BP, Feng J, Zhou JJ, Xie ZZ, Liang C, et al.
    Trop Biomed, 2020 Dec 01;37(4):852-863.
    PMID: 33612738 DOI: 10.47665/tb.37.4.852
    Fructose-1,6-bisphosphate aldolase (FbA), a well characterized glycometabolism enzyme, has been found to participate in other important processes besides the classic catalysis. To understand the important functions of three fructose-1,6-bisphosphate aldolases from Clonorchis sinensis (CsFbAs, CsFbA-1/2/3) in host-parasite interplay, the open reading frames of CsFbAs were cloned into pET30a (+) vector and the resulting recombinant plasmids were transformed into Escherichia coli BL21 (DE3) for expression of the proteins. Purified recombinant CsFbAs proteins (rCsFbAs) were approximately 45.0 kDa on 12% SDS-PAGE and could be probed with each rat anti-rCsFbAs sera by western blotting analysis. ELISA and ligand blot overlay indicated that rCsFbAs of 45.0 kDa as well as native CsFbAs of 39.5 kDa from total worm extracts and excretory-secretory products of Clonorchis sinensis (CsESPs) could bind to human plasminogen, and the binding could be efficiently inhibited by lysine analog ε-aminocaproic acid. Our results suggested that as both the components of CsESPs and the plasminogen binding proteins, three CsFbAs might be involved in preventing the formation of the blood clot so that Clonorchis sinensis could acquire enough nutrients from host tissue for their successful survival and colonization in the host. Our work will provide us with new information about the biological function of three CsFbAs and their roles in hostparasite interplay.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism
  16. Fulltext Experimental Infection of Syrian Hamsters With Aerosolized Nipah Virus
    Escaffre O, Hill T, Ikegami T, Juelich TL, Smith JK, Zhang L, et al.
    J Infect Dis, 2018 10 05;218(10):1602-1610.
    PMID: 29912426 DOI: 10.1093/infdis/jiy357
    Background: Nipah virus (NiV) is a paramyxovirus (genus Henipavirus) that can cause severe respiratory illness and encephalitis in humans. Transmission occurs through consumption of NiV-contaminated foods, and contact with NiV-infected animals or human body fluids. However, it is unclear whether aerosols derived from aforesaid sources or others also contribute to transmission, and current knowledge on NiV-induced pathogenicity after small-particle aerosol exposure is still limited.

    Methods: Infectivity, pathogenicity, and real-time dissemination of aerosolized NiV in Syrian hamsters was evaluated using NiV-Malaysia (NiV-M) and/or its recombinant expressing firefly luciferase (rNiV-FlucNP).

    Results: Both viruses had an equivalent pathogenicity in hamsters, which developed respiratory and neurological symptoms of disease, similar to using intranasal route, with no direct correlations to the dose. We showed that virus replication was predominantly initiated in the lower respiratory tract and, although delayed, also intensely in the oronasal cavity and possibly the brain, with gradual increase of signal in these regions until at least day 5-6 postinfection.

    Conclusion: Hamsters infected with small-particle aerosolized NiV undergo similar clinical manifestations of the disease as previously described using liquid inoculum, and exhibit histopathological lesions consistent with NiV patient reports. NiV droplets could therefore play a role in transmission by close contact.

    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism
  17. Molecular and allergenic characterization of recombinant tropomyosin from mud crab Scylla olivacea
    Azemi NFH, Misnan R, Keong BP, Mokhtar M, Kamaruddin N, Fah WC, et al.
    Mol Biol Rep, 2021 Oct;48(10):6709-6718.
    PMID: 34427887 DOI: 10.1007/s11033-021-06661-x
    BACKGROUND: Tropomyosin is a major allergen in crustaceans, including mud crab species, but its molecular and allergenic properties in Scylla olivacea are not well known. Thus, this study aimed to produce the recombinant tropomyosin protein from S. olivacea and subsequently investigate its IgE reactivity.

    METHODS AND RESULTS: The tropomyosin gene was cloned and expressed in the Escherichia coli system, followed by SDS-PAGE and immunoblotting test to identify the allergenic potential of the recombinant protein. The 855-base pair of tropomyosin gene produced was found to be 99.18% homologous to Scylla serrata. Its 284 amino acids matched the tropomyosin of crustaceans, arachnids, insects, and Klebsiella pneumoniae, ranging from 79.03 to 95.77%. The tropomyosin contained 89.44% alpha-helix folding with a tertiary structure of two-chain alpha-helical coiled-coil structures comprising a homodimer heptad chain. IPTG-induced histidine tagged-recombinant tropomyosin was purified at the size of 42 kDa and confirmed as tropomyosin using anti-tropomyosin monoclonal antibodies. The IgE binding of recombinant tropomyosin protein was reactive in 90.9% (20/22) of the sera from crab-allergic patients.

    CONCLUSIONS: This study has successfully produced an allergenic recombinant tropomyosin from S. olivacea. This recombinant tropomyosin may be used as a specific allergen for the diagnosis of allergy.

    Matched MeSH terms: Recombinant Proteins/genetics*; Recombinant Proteins/immunology*
  18. Fulltext Using transgenic plants and modified plant viruses for the development of treatments for human diseases
    Loh HS, Green BJ, Yusibov V
    Curr Opin Virol, 2017 10;26:81-89.
    PMID: 28800551 DOI: 10.1016/j.coviro.2017.07.019
    Production of proteins in plants for human health applications has become an attractive strategy attributed by their potentials for low-cost production, increased safety due to the lack of human or animal pathogens, scalability and ability to produce complex proteins. A major milestone for plant-based protein production for use in human health was achieved when Protalix BioTherapeutics produced taliglucerase alfa (Elelyso®) in suspension cultures of a transgenic carrot cell line for the treatment of patients with Gaucher's disease, was approved by the USA Food and Drug Administration in 2012. In this review, we are highlighting various approaches for plant-based production of proteins and recent progress in the development of plant-made therapeutics and biologics for the prevention and treatment of human diseases.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/metabolism*
  19. Human neonatal Fc receptor as a new potential antibody binding protein for antibody immobilization
    Ng WK, Lim TS, Lai NS
    Biotechnol Appl Biochem, 2018 Jul;65(4):547-553.
    PMID: 29280199 DOI: 10.1002/bab.1636
    A critical challenge in producing an antibody-based assay with the highest reproducibility and sensitivity is the strategy to immobilize antibodies to solid phase. To date, numerous methods of antibody immobilization were reported but each was subjected to its advantages and limitations. The current study proposes a new potential antibody binding protein, the human neonatal fragment crystallizable (Fc) receptor. This protein has shown its high affinity to the Fc of antibody either in vivo or in vitro. Human neonatal Fc receptor is a heterodimer constructed by p51 α-heavy chain and β2-microglobulin light chain; however, the binding sites toward the antibody are located in the p51 α-heavy chain. Hence, vector cloning and recombinant protein expression were carried out to express the p51 α-heavy chain of the human neonatal Fc receptor (hFcRn-α). The recombinant protein expressed, hFcRn-α, was adopted to pin rabbit IgG against hepatitis B virus surface antigen to a solid phase. A sandwich enzyme-linked immunosorbent assay was further developed to evaluate the efficiency of hFcRn-α-directed immobilization in antigen detection. The result was compared with the conventional physical adsorption method. The findings demonstrated that human neonatal Fc receptor was efficient in pinning antibodies and generating higher signals compared with the physical adsorption of antibody.
    Matched MeSH terms: Recombinant Proteins/biosynthesis; Recombinant Proteins/immunology
  20. Cloning and expression of Toxoplasma gondii dense granule antigen 2 (GRA2) gene by Pichia pastoris
    Lau YL, Fong MY, Idris MM, Ching XT
    Southeast Asian J Trop Med Public Health, 2012 Jan;43(1):10-6.
    PMID: 23082548
    Detection of Toxoplasma gondii infection is essential in pregnant women and immunosuppressed patients. Numerous studies have shown that the recombinant production of several Toxoplasma antigens, including dense granule antigens (GRAs) has high potential as diagnostic reagents. In the present study, we produced GRA2 using Pichia pastoris system. RNA of T. gondii RH strain tachyzoite was used as a template to produce cDNA clones of full-length GRA2 via reverse transcriptase PCR. Amplicons were inserted into pPICZalpha A and the recombinant plasmid transformed into P. pastoris, X-33 strain. The expressed recombinant protein was identified by SDS-PAGE and Western blotting. A recombinant protein of -28 kDa was produced, which could be detected by toxoplasmosis positive human sera indicating that the recombinant protein retained its antigenicity. The present study indicates that P. pastoris-expressed GRA2 should be useful for detection of Toxoplasma infection.
    Matched MeSH terms: Recombinant Proteins/genetics*; Recombinant Proteins/metabolism
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