ORCID Profile
0000-0002-6123-7437
Current Organisation
Hue University
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Publisher: Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications)
Date: 30-06-2022
Abstract: Enhanced Green Fluorescent Protein (eGFP) shows much stronger fluorescence than its ancestor, Green Fluorescent Protein (GFP), thus has been widely applied as a reporter for biomedical research. In this study, we reported the expression of a synthetic codon optimized gene encoding eGFP in Escherichia coli (E. coli). The gene was cloned into two expression vectors, pQE30 and pColdII and the resulting recombinant vectors were transformed into E. coli M15 and BL21 De3 RIL codon plus strains, respectively. The expression levels of functional eGFP showed a temperature dependent pattern, in which lowering the induction temperature increased the amount of functional eGFP. Surprisingly, eGFP showed a phenomenon called auto-induction when E. coli TOP10 cells carrying recombinant pQE30 and pColdII were grown on Luria Broth plates. The recombinant eGFP showed robust stability even at room temperature, thus greatly facilitated its purification and handling. Mouse polyclonal antibodies were conveniently generated against the protein. Besides its potential application as a reporter gene in E. coli, the gene and its expression systems reported here are extremely useful as models for teaching recombinant DNA technology at undergraduate level.
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.JBIOSC.2014.06.005
Abstract: A fusion construct (Tet-EDIII-Co1) consisting of an M cell-specific peptide ligand (Co1) at the C-terminus of a recombinant tetravalent gene encoding the amino acid sequences of dengue envelope domain III (Tet-EDIII) from four serotypes was expressed and tested for binding activity to the mucosal immune inductive site M cells for the development of an oral vaccine. The yeast episomal expression vector, pYEGPD-TER, which was designed to direct gene expression using the glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, a functional signal peptide of the amylase 1A protein from rice, and the GAL7 terminator, was used to clone the Tet-EDIII-Co1 gene and resultant plasmids were then used to transform Saccharomyces cerevisiae. PCR and back-transformation into Escherichia coli confirmed the presence of the Tet-EDIII-Co1 gene-containing plasmid in transformants. Northern blot analysis of transformed S. cerevisiae identified the presence of the Tet-EDIII-Co1-specific transcript. Western blot analysis indicated that the produced Tet-EDIII-Co1 protein with the expected molecular weight was successfully secreted into the culture medium. Quantitative Western blot analysis and ELISA revealed that the recombinant Tet-EDIII-Co1 protein comprised approximately 0.1-0.2% of cell-free extracts (CFEs). In addition, 0.1-0.2 mg of Tet-EDIII-Co1 protein per liter of culture filtrate was detected on day 1, and this quantity peaked on day 3 after cultivation. In vivo binding assays showed that the Tet-EDIII-Co1 protein was delivered specifically to M cells in Peyer's patches (PPs) while the Tet-EDIII protein lacking the Co1 ligand did not, which demonstrated the efficient targeting of this antigenic protein through the mucosal-specific ligand.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2021
DOI: 10.1007/S10529-021-03161-7
Abstract: To explore Saccharomyces cerevisiae as an expression platform for dengue oral immune complex vaccine development. Molecular engineering was applied to create a fusion gene construct (scEDIII-PIGS) consisting of a yeast codon optimized sequence encoding for a synthetic consensus dengue envelope domain III (scEDIII) followed by a modified IgG Fc domain (PIGS). Northern blot showed transcription of the target gene, with a temporal expression pattern similar to those from previous work. Western blot showed assembly of various immune complexes from monomer to hexamer. Partial purification of scEDIII-PIGS was also attempted to demonstrate the feasibility of yeast system for immune complex vaccine development. Approximately 1 mg of scEDIII-PIGS can be produced from 1 l culture. This work demonstrated for the first time that various immunocomplex structures of our target protein could be efficiently produced in S. cerevisiae for future application in developing oral and injectable vaccines against various pathogens.
Publisher: Springer Science and Business Media LLC
Date: 16-02-2018
Publisher: Informa UK Limited
Date: 24-08-2023
Publisher: Journal of Experimental Biology and Agricultural Sciences
Date: 30-12-2021
DOI: 10.18006/2021.9(6).871.880
Abstract: Chitinases from the genus Trichoderma fungi are mainly responsible for their anti-fungal activities, which allow them to become the most widely used fungal biocontrol. Therefore, several Trichoderma chitinases have been cloned and expressed to facilitate their production and applications. A previous study of the same authors has characterized an endochitinase from a relatively novel Trichoderma spp., Trichoderma asperellum. To produce this enzyme more economically and efficiently, we reported the synthesis and expression of its synthetic encoding gene in the Escherichia coli M15 strain and established the optimal conditions for preparative scale production of the enzyme in its functional form. By lowering the induction temperatures, we observed substantial improvement in the expression levels of the active enzyme. At 30 oC and 0.5 mM IPTG induction, 1 L of cells yielded approximately 80 - 100 mg of soluble protein, accounting for about 9-11 % of total soluble protein. This figure may be an underestimation of the actual yield, as deduced from the SDS-PAGE data. The recombinant enzyme can be retrieved by simple repeated freezing and thawing cycles and purified to near homogeneity using Ni-NTA chromatography. The purified enzyme showed in vitro colloidal chitin hydrolysis activity. These results could be scaled up to produce soluble 42 kDa chitinase in E. coli. The study demonstrated an economical method to produce chitinases for various agricultural and environmental applications.
Publisher: Springer Science and Business Media LLC
Date: 22-08-2018
DOI: 10.1007/S12275-018-8297-7
Abstract: The group of butyrate-producing bacteria within the human gut microbiome may be associated with positive effects on memory improvement, according to previous studies on dementia-associated diseases. Here, fecal s les of four elderly Japanese diagnosed with Alzheimer's disease (AD) were used to isolate butyrate-producing bacteria. 226 isolates were randomly picked, their 16S rRNA genes were sequenced, and assigned into sixty OTUs (operational taxonomic units) based on BLASTn results. Four isolates with less than 97% homology to known sequences were considered as unique OTUs of potentially butyrate-producing bacteria. In addition, 12 potential butyrate-producing isolates were selected from the remaining 56 OTUs based on scan-searching against the PubMed and the ScienceDirect databases. Those belonged to the phylum Bacteroidetes and to the clostridial clusters I, IV, XI, XV, XIVa within the phylum Firmicutes. 15 out of the 16 isolates were indeed able to produce butyrate in culture as determined by high-performance liquid chromatography with UV detection. Furthermore, encoding genes for butyrate formation in these bacteria were identified by sequencing of degenerately primed PCR products and included the genes for butyrate kinase (buk), butyryl-CoA: acetate CoAtransferase (but), CoA-transferase-related, and propionate CoA-transferase. The results showed that eight isolates possessed buk, while five isolates possessed but. The CoA-transfer-related gene was identified as butyryl-CoA:4-hydroxybutyrate CoA transferase (4-hbt) in four strains. No strains contained the propionate CoA-transferase gene. The biochemical and butyrate-producing pathways analyses of butyrate producers presented in this study may help to characterize the butyrate-producing bacterial community in the gut of AD patients.
Publisher: Hue University
Date: 28-11-2018
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.PEP.2013.01.009
Abstract: A synthetic consensus gene was designed based on residues of the amino acid sequences of dengue envelope domain III (scEDIII) from all four serotypes, and codon optimization for expression was conducted using baker's yeast, Saccharomyces cerevisiae. The synthetic gene was cloned into a yeast episomal expression vector, pYEGPD-TER, which was designed to direct cloned gene expression using the glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, a functional signal peptide of the amylase 1A protein from rice, and the GAL7 terminator. PCR and back-transformation into Escherichia coli confirmed the presence of the scEDIII gene-containing plasmid in the transformants. Northern blot analysis showed the presence of the scEDIII-specific transcript. Western blot analysis indicated that expressed scEDIII, with mobility similar to purified EDIII from E. coli, was successfully secreted into the culture media. Quantitative ELISA revealed that the recombinant scEDIII comprised approximately 0.1-0.6% of cell-free extract. In addition, 0.1-0.6 mg of scEDIII protein per liter of culture filtrate was detected on day 1 and peaked on day 3 after cultivation. The secreted scEDIII protein can be purified to ≥90% purity with 85% recovery using a simple ion-exchange FPLC followed by molecular weight cut-off. Upon administration of the purified protein to mice, mouse sera contained antibodies that were specific to all four serotypes of dengue virus. Moreover, a balanced immune response against all four serotypes was observed, suggesting that it may be possible to develop an effective tetravalent dengue vaccine using S. cerevisiae.
Publisher: Termedia Sp. z.o.o.
Date: 2018
Publisher: The Korean Society for Plant Biotechnology
Date: 30-09-2019
Publisher: Springer Science and Business Media LLC
Date: 2016
DOI: 10.1515/CHEMPAP-2015-0210
Abstract: Two genes coding endo-β-1,4-glucanases were cloned from Trichoderma asperellum PQ34 which was isolated from Thua Thien Hue province, Vietnam. The expression of these genes in Pichia pastoris produced two enzymes with molecular masses of approximately 46 kDa (about 42 kDa of enzymes and 4 kDa of signal peptide). The effects of induction time and temperature, inducer concentration, and culture medium on the endo-β-1,4-glucanase activity were investigated. The results showed that the highest total activities of two endo-β-1,4-glucanases were approximately 4.7 × 10
Publisher: Bentham Science Publishers Ltd.
Date: 27-11-2018
DOI: 10.2174/1389201019666181008112244
Abstract: Curcuminoid genes have an important role in the biosynthesis of curcumin, a valuable bioactive compound, in Curcuma species. However, there have not been any reports of these genes in Curcuma zedoaria. The present work reports on the isolation of genes encoding enzymes in curcuminoid metabolic pathway and their expression in C. zedoaria. The primers were designed from untranslation regions of DCS, CURS1, CURS2 and CURS3 genes which are involved in curcuminoid biosynthesis in C. longa to isolate the corresponding fulllength genes in C. zedoaria. RT-PCR lification and HPLC analysis are used to estimate the expression of genes and biosynthesis of curcumin in both rhizome and callus. The results showed that all four genes from C. zedoaria (named CzDCS, CzCURS1, CzCURS2 and CzCURS3) and C. longa have a high identity (approximately 99%) and lengths of genes from C. zedoaria are 1382, 1240, 1288 and 1265 nu, respectively. CzCURS1, 2 and 3 genes have one intron while CzDCS has two introns. RT-PCR lification indicated that curcuminoid genes expressed mRNA in rhizome and callus of C. zedoaria. Curcumin, a major component of curcuminoids, was also found in callus by HPLC analysis. The sequence information of DCS and CURS1-3 genes in C. zedoaria will be very valuable for a subsequent study on the effects of elicitors on the transcription of genes involved in curcuminoid biosynthesis pathway.
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.MIMET.2012.09.014
Abstract: In previous studies, the biological characteristics of the fungus Cladosporium phlei and its genetic manipulation by transformation were assessed to improve production of the fungal pigment, phleichrome, which is a fungal perylenequinone that plays an important role in the production of a photodynamic therapeutic agent. However, the low production of this metabolite by the wild-type strain has limited its application. Thus, we attempted to clone and characterize the genes that encode polyketide synthases (PKS), which are responsible for the synthesis of fungal pigments such as perylenequinones including phleichrome, elsinochrome and cercosporin. Thus, we performed genomic DNA PCR using 11 different combinations of degenerate primers targeting conserved domains including β-ketoacyl synthase and acyltransferase domains. Sequence comparison of the PCR licons revealed a high homology to known PKSs, and four different PKS genes showing a high similarity to three representative types of PKS genes were lified. To obtain full-length PKS genes, an ordered gene library of a phleichrome-producing C. phlei strain (ATCC 36193) was constructed in a fosmid vector and 4800 clones were analyzed using a simple pyramidal arrangement system. This hierarchical clustering method combines the efficiency of PCR with enhanced specificity. Among the three representative types of PKSs, two reducing, one partially reducing, and one non-reducing PKS were identified. These genes were subsequently cloned, sequenced, and characterized. Biological characterization of these genes to determine their roles in phleichrome production is underway, with the ultimate aim of engineering this pathway to overproduce the desired substance.
Publisher: Informa UK Limited
Date: 03-2017
Publisher: Springer Science and Business Media LLC
Date: 14-09-2018
Publisher: Research Square Platform LLC
Date: 25-03-2022
DOI: 10.21203/RS.3.RS-1487302/V1
Abstract: This study reports the expression of the 42 kDa chitinase genes from Trichoderma asperellum SH16 in peanut (Arachis hypogaea) roots under the regulation of tissue-specific Asy promoter through Agrobacterium tumefaciens-mediated transformation. The 42 kDa chitinase genes, including one wild-type sequence (Chi42) and two synthetic sequences (syncodChi42-1 and syncodChi42-2) which were optimized for codon usage for plant expression, were incorporated into the peanut genome and successfully expressed in their roots. The investigation revealed that chitinase from two synthetic genes had higher activity than that from the wild-type gene, about 901 U/mg (140 U/mL) and 1124 U/mg (197 U/mL) vs about 739 U/mg (105 U/mL), respectively. Transgenic peanut roots also exhibited extracellular chitinase activity which was driven by signal peptide of rice amylase 3D gene against the pathogenic fungus Sclerotium rolfsii under in vitro conditions. The higher chitinase activity of two synthetic genes in peanut roots promises potential applications in the field of transgenic crops against phytopathogenic fungi.
No related grants have been discovered for Nguyen Ngoc Luong.