• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.504-510
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• 1993

The effect of AcNPV infection conditions such as serum concentration, pH, CaCl2, lysosomotropic agent, cell density at infection, agitation, aeration and nutritional supplementattion on recombinant protein production in Spodoptera frugiperda 21 cells was investigated using tissue culture flask, bottle and spinner flask. It was shown that serum, CaCl2, pH and cell density at infection affected recombinant production. The lysosomotropic agent did not significantly influence recombinant protein production.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.1
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• pp.1-5
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• 2017

Bone morphogenetic protein 2 (BMP2) plays an important role in the development of bone and cartilage. It is involved in the hedgehog pathway, TGF beta signaling pathway, and in cytokine-cytokine receptor interaction. It is involved also in cardiac cell differentiation and epithelial to mesenchymal transition. In this study, We expressed human BMP2 (hBMP2) recombinant protein using Baculovirus Expression Vector System (BEVS) in Sf9 insect cells. The hBMP2 cDNA was cloned into baculovirus transfer vector, pBacgus-4x-1 and recombinant baculovirus was screened out through X-gal and GUS-fusions assay. Western blot analysis shown that molecular weight of hBMP2 recombinant protein was about 44.71 kDa.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.355-362
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• 2000

The Herpes simplex virus type 1 (HSV-1) glycoprotein B (gB) gene in the pHLA-21 plasmid was inserted into a baculovirus (Hyphantria cunea nuclear polyhedrosis virus) expression vector (lacZ-HcNPV) to construct a recombinant virus gB-HcNPV expressing gB. Spodoptera frugiperda cells infected with this recombinant virus synthesized and processed gB of approximately 120 kDa, which cross-reacted with the monoclonal antibody to gB. The recombinant gB was identified on the membrane of the insect cells using an immunofluorescence assay. Antibodies to this recombinant raised in mice recognize the viral gB and neutralized the infectivity of the HSV-1 in vitro. These results show that the gB gene has the potential to be expressed in insect cells. They also demonstrate that it is possible to produce a mature protein by gene transfer in eukaryotic cells, and indicate the utility of the lacZ-HcNPV-insect cell system for producing and characterizing eukaryotic proteins. Furthermore, the neutralizing antibodies would appear to protect mice against HSV. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.20-27
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• 2016

Lactobacillus kefiranofaciens ZW3 was obtained from kefir grains, which have high lactose hydrolytic activity. In this study, a heterodimeric LacLM-type β-galactosidase gene (lacLM) from ZW3 was isolated, which was composed of two overlapping genes, lacL (1,884 bp) and lacM (960 bp) encoding large and small subunits with calculated molecular masses of 73,620 and 35,682 Da, respectively. LacLM, LacL, and LacM were expressed in Escherichia coli BL21(DE3) and these recombinant proteins were purified and characterized. The results showed that, compared with the recombinant holoenzyme, the recombinant large subunit exhibits obviously lower thermostability and hydrolytic activity. Moreover, the optimal temperature and pH of the holoenzyme and large subunit are 60℃ and 7.0, and 50℃ and 8.0, respectively. However, the recombinant small subunit alone has no activity. Interestingly, the activity and thermostability of the large subunit were greatly improved after mixing it with the recombinant small subunit. Therefore, the results suggest that the small subunit might play an important role in maintaining the stability of the structure of the catalytic center located in the large subunit.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.706-709
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• 2002

Bacterial bioluminescence has been known to be a highly valuable reporter system for its potential application as an effective and simple environmental monitoring method for toxic compounds. In this short report, we constructed a streptomycetes-Escherichia coli shuttle vector-containing bioluminescence system and evaluated its potential application for toxic compounds monitoring. The luxAB biolurninescence genes from Vibrio harveyi were cloned into a streptornycetes-E. coli shuttle vector (named pESK004) and functionally expressed in Streptomyces lividans. The recombinant S. lividans containing pESK004 exhibited an optimal biolurninescence at the optical density ($OD_{600\;nm}$) of 0.4-0.5 and aldehyde concentration of 0.005%. When the recombinant bioluminescence streptomycetes was exposed to a toxic compound such as heavy metals, chlorinated phenols, or pesticides, the bioluminescence was decreased proportionally to the concentration of toxic compound in the assay mixture. The $EC_{50}$ (effective concentration to decrease 50% of the bioluminescence prior to exposure) values in the recombinant biolurninescence streptomycetes for mercury, 2,4-dichlorophenol, and malathion were measured at 2.2 ppm, 144.0 ppm, and 82.4 ppm, respectively. The degree of sensitivity and specificity pattern toward these toxic compounds characterized in this recombinant bioluminescence streptomycetes were unique when compared with previously reported bacterial bioluminescence systems, and this revealed that a recombinant bioluminescence streptomycetes might provide an alternative or complementary system for potential environmental monitoring.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.449-456
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• 2003

The VP2 gene of aquatic birnavirus, Korean isolate (GC-1) was cloned and expressed using the baculovirus expression system. The VP2 gene and VP2 partial gene, which contained a neutralizing epitope, were constructed for recombinant transfer vectors, for baculovirus expression. The expressed recombinant proteins were confirmed by indirect immuno fluorescence antibody (IFA), SDS-PAGE and Western blot. The level of expression was checked at regular time using IFA and Western blot. To measure the neutralizing activity of recombinant proteins against GC-1 strain, the antisera against recombinant proteins were produced by using guinea pigs. The result showed that the antisera neutralized the GC-1 strain. However, the neutralizing titer was higher in antisera against the VP2 gene expressed recombinant protein than that of VP2 partial gene recombinant protein.

• BMB Reports
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• v.28 no.3
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• pp.216-220
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• 1995

cDNA for human cholesteryl ester transfer protein (CETP), a potent atherogenic plasma protein that redistributes the neutral lipids among lipoproteins, was expressed in recombinant vaccinia virus-infected cells (CV-1). Two insertion vectors regulated by different promoters were constructed. The vectors were introduced into human thymidine kinase-negative ($TK^-$) 1438 cells infected with wild-type vaccinia virus (WR strain). Recombinant viruses were selected with 5-bromodeoxyuridine (BUdR) and X-gal and identified with DNA dot blot analysis (vSC11-CETP and vTM1-CETP). The CETP cDNA insert in the recombinant vaccinia virus genome was identified by Southern blot analysis. Transcription of CETP cDNA in CV-1 cells infected with recombinant vaccinia virus was monitored by Northern blot analysis using the CETP cDNA as a probe. Positive signals were detected at 1.8 kb in cells infected with vSC11-CETP and at 2.3 kb in cells infected with vTM1-CETP. The recombinant vaccinia virus-infected CV-1 cells were shown to produce functional CETP when the culture medium was subjected to the CETP assay.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.954-958
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• 2009

Effects of controlled- and uncontrolled-pH operations on phenylalanine ammonia lyase (PAL) production by a recombinant Escherichia coli strain were investigated at uncontrolled-pH ($pH_{UC}$) and controlled-pH ($pH_C$) of 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 in bioreactor systems. The results showed that the recombinant PAL activity was improved significantly by controlled pH strategy. Among the $pH_C$ operations, the highest PAL activities were obtained under $pH_C$ 7.5 strategy where cell mass ($OD_{600\;nm}$) and PAL activity was 1.3 and 1.8 fold higher than those of $pH_{UC}$, respectively. The maximum PAL activity reached 123 U/g. The $pH_C$ 7.5 strategy made recombinant plasmid more stable and therefore allowed easier expression of PAL recombinant plasmid, which increased PAL production. It was indicated that the new approach (controlled-pH strategy) obtained in this work possessed a high potential for the industrial production of PAL, especially in the biosynthesis of L-phenylalanine.

• BMB Reports
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• v.40 no.3
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• pp.333-340
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• 2007

Gene encoding cyclodextrin glycosyltransferase (CGTase), from thermotolerant Paenibacillus sp. T16 isolated from hot spring area in northern Thailand, was cloned and expressed in E. coli (JM109). The nucleotide sequences of both wild type and transformed CGTases consisted of 2139 bp open reading frame, 713 deduced amino acids residues with difference of 4 amino acid residues. The recombinant cells required 24 h culture time and a neutral pH for culture medium to produce compatible amount of CGTase compared to 72 h culture time and pH 10 for wild type. The recombinant and wild-type CGTases were purified by starch adsorption and phenyl sepharose column chromatography and characterized in parallel. Both enzymes showed molecular weight of 77 kDa and similar optimum pHs and temperatures with recombinant enzyme showing broader range. There were some significant difference in pH, temperature stability and kinetic parameters. The presence of high starch concentration resulted in higher thermostability in recombinant enzyme than the wild type. The recombinant enzyme was more stable at higher temperature and lower pH, with lower $K_m$ for coupling reaction using cellobiose and cyclodextrins as substrates.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.139-146
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• 1998

Recombinant polioviruses have been developed by many research groups for use as vaccine vector because poliovirus induces mucosal immunity as well as humoral immunity through oral uptake. We assessed the potential use of poliovirus as a T-cell epitope carrier. Recombinant poliovirus V129 5L was constructed to have a substituted T-helper epitope from the core protein of Hepatitis B virus at neutralization antigenic site 1 on its VP1 capsid protein. The recombinant virus replicated less efficiently than type 1 poliovirus Mahoney strain. The V129 5L formed a little smaller plaques than the Mahoney strain and showed some 1.25 log unit lower titer at the peak in the one-step growth kinetics though it had similar growth profile to that of the Mahoney strain. Since V129 5L recombinant virus was genetically stable even after 24 successive passages in HeLa cells, the antigenic site 1 on VP1 capsid protein was confirmed for its ability of carrying T cell epitope. The genetic stability of V129 5L also indicated that recombinant poliovirus can be successfully utilized for the development of the multivalent vaccines.