• KSBB Journal
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• v.13 no.6
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• pp.656-661
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• 1998

Hantaan virus belonging to the genus Hantavirus and family Bunyaviridae causes an acute severe illness of human, Haemorrhagic Fever with Renal Syndrome (HFRS). It is a rodent host-borne pathogen and distributed in Asia and Eastern Europe. Hantaviruses have three major antigens, i.e., G1, G2 glycoproteins and nucleocapsid protein (N). Among them, nucleocapsid protein was reported to be the most invaluable antigen as for diagnosis. We have cloned and expressed Hantaan viral nucleocapsid gene in E. coli BL21(DE3). In this study, we have tried to purify the nucleocapsid protein produced by recombinant E. coli, and could attained a purity of >90% by anti-N monoclonal antibody-coupled immunoaffinity chromatography or phenyl sepharose hydrophobic interaction chromatography.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.101-106
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• 1996

Tobacco mosaic virus (TMV) tomato strain was isolated from tomato "Seo-Kwang" in Korea. The virion was purified by density gradient centrifugation, and total viral RNA was isolated from the purified particles. Coat protein (CP) cDNA of the virus was synthesized by RT-PCR, and the purified cDNA fragment was subcloned to pBluescript II SK-. The analysis of nucleotide sequence showed that this cDNA was 693 nucleotides long from the insert of clone p1571 and p1572 which contain complete codons of the viral coat protein gene (474 nucleotides) and 3' untranslated region. The nucleotides of coat protein encoding cDNA of the strain were 6 nucleotides less than that of TMV common strain isolated from tobacco plant in Korea. The CP gene showed 70% maximum homology with that of the common strain in the nucleotide level and 86% maximum homology in amino acid level.cid level.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.466-470
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• 2008

Human cytomegalovirus expresses an unusual protein kinase UL97, a member of ${H_V}{U_L}$ family of protein kinase. UL97 can phosphorylate nucleoside analogs such as ganciclovir as well as protein/peptide. It has previously been reported that UL97 is able to phosphorylate a KESYSVYVYKV peptide and that P+5 position (K) is important. We examined the extent of contribution of other positions (P-4 through P+6) of the peptide to be substrate of UL97 using alanine substituted peptides (Ala scanning) and deleted peptides. The result suggested that the E (P-2) is negative effect and P+5 (K) is still important. The peptide YSVYVYK is the shortest substrate enough to show high activity, which could be a starting point to develop peptidomimetic drug. This study would give important information to deeply understand the substrate specificity of UL97 and develop an antiviral drug using the small peptide identified here.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.292-294
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• 2001

Cystocin is identified from the screening of Streptomyces sp GCA0001. It is isolated from the culture of streptomyces sp GCA0001. A white coloured cystocin is structurally similar to puromycin, an antibiotic produced by streptomyces albonrger. Like puromycin, cystocin possesses an antibacterial, antitumour and antiviral activity. It impairs the protein synthesis by inhibiting polypeptide chain elongation.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.46-52
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• 1998

Retroviral integrase is required for integration of viral DNA into the host cell chromosome. Human immunodeficiency virus type-1 integrase was partially purified as a part of a fusion protein linked to a maltose-binding protein and characterized in terms of an endonucleolytic activity. The concentration of the fusion protein purified through an amylose column was about 12mg/ml. Indicating that the solubility of the fusion protein is highly increased by the presence of a maltose-binding protein, considering that the integrase protein alone is poorly solubilized. The endonucleolytic activity of the fusion protein was detected at 0.1 to 1.OmM $Mn^{++}$ ion, but not at any concentrations tested of $Mn^{++}$ ion.

• Research in Plant Disease
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• v.22 no.1
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• pp.32-37
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• 2016

In this work, major outer capsid protein (P10) encoded by genome segment S10 of Rice black-streaked dwarf virus (RBSDV) was expressed in Escherichia coli. Genomic dsRNA was extracted from RBSDV-miryang isolate infected rice plants. Based on the sequence of S10 (RBSDV-miryang, GenBank JX994211), a pair of S10 specific primers were designed and used to amplify the fragment encoding the N-part of P10. We amplified the partial gene (S10 1-834 nt) of RBSDV P10 (1-278 aa) by RT-PCR. Amplified RBSDV S10 (1-834 nt) was cloned into the expression vector pET32a (+). Recombinant RBSDV S10 (1-834 nt) was expressed in E. coli BL21(DE3) and purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity column. We successfully obtained P10 partial protein of RBSDV and the purified protein was used to immunize rabbits. The resulting polyclonal antiserum specifically recognized RBSDV from infected plant in both Western blotting and enzyme-linked immunosorbent assay. In this study, we provide purified RBSDV P10 (1-278 aa), which would be good material for the serological study of RBSDV-miryang isolates.

• Journal of fish pathology
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• v.11 no.1
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• pp.43-50
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• 1998

In order to determine whether the tumor-inducing iridoviruses and the mortality-associated iridoviruses from cultured marine fish in Korea belong to same type, we compared the immunological characteristics of these viruses. The electrophoretical pattern of structural proteins of the tumor-inducing was different from that of the mortality-associated iridoviruses. The antigenicity of structural proteins of these viruses were identified by Western blotting using two monoclonal antibodies against tumor-inducing iridovirus. Two monoclonal antibodies recognized a 150 kDa structural protein of tumor-inducing iridoviruses showed. However, the structural proteins of the mortality-associated iridoviruses did not react with these monoclonal antibodies. These results demonstrate that the antigenicity of the structural proteins of tumor-inducing iridovirus is different from that of mortality-associated iridovirus, indicating that these two iridoviruses belong to different types.

• Journal of Life Science
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• v.34 no.7
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• pp.493-499
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• 2024

Antimicrobial peptides are antimicrobial substances inherent in animals and plants, with strong antibacterial activity even in small amounts and with various other functions such as antiviral and antioxidant actions. Plants can be grown with just water and sunlight, allowing for their mass production at low costs. However, transforming a chloroplast into one that produces antimicrobial peptides, rather than growing plants, increases the amount of protein expression and minimizes contamination of the ecosystem because gene transfer by pollen does not occur. In that context, using transgenic plant chloroplasts to produce recombinant proteins increases protein degradation and reduces the solubility of proteins. To solve this problem, we fused SUMO, a fusion protein, with a recombinant protein. We also used a 6xHis tag to purify the fusion protein. The antimicrobial peptide stomoxyn is an antibacterial substance found in stable flies. Stomoxyn has an α-helix structure and is amphiphilic, which allows it to dissolve bacterial cell membranes. In this study, we constructed a transformation vector to express stomoxyn in both plant chloroplasts and Escherichia coli and used this vector to confirm the expression of stomoxyn in E. coli. The expression of the protein was then confirmed in E. coli using a transformation vector. The expressed stomoxyn was purified by nickel column and SUMOase treatment, and its antibacterial activity was confirmed using an agar diffusion assay. The EGFP gene was used to ensure that the transformed vector was inserted into the chloroplast.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.1-5
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• 1990

The coding sequence of hepatitis B viral core antigen (HBcAg) (subtype adr) contains two in-phase initiation codons, one for precore and the other for core antigen gene. To study the expression of core antigen and the role of precore region, the coding sequence of HBcAg with or without precore (pre-C) region were subcloned into yeast expression vector containing phosphoglycerate kinase (PGK) promoter. To study the role of upstream region in the expression of the core antigen, a series of 5' deletion mutants were also subcloned into the vector. After transformation into various host strains, the expression of HBcAg were analysed by radio-immunoassat. Under optimal condition of core antigen gene expression in yeast, the highest amount of antigen was detected in the cell line SHY4 containing pGKHBc plasmid composed of the yeast PGK gene promoter, terminator and C-gene. Regardless of the presence of precore region, core antigen was not detected in the medium but in cell extract. These results suggest that precore region cannot affect the secretion of core antigen in Saccharomyces cerevisiae.

• Research in Plant Disease
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• v.10 no.3
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• pp.194-197
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• 2004

Incidence of tobamovirus diseases was 100％ at late growth stage of green pepper on hydroponic systems in plastic house. Infection frequency of the diseases showed 34％ of Pepper mild mottle virus (PMMoV), 41.5％ of Tobacco mild green mottle virus (TMGMV), and 24.5％ of the co-infected viruses. The two viruses specifically reacted in DAS-ELISA prepared with each polyclonal antibody. A total of 77 pure tobamovirus isolates obtained from the crops was tested for pathotype determination. The isolation frequency of tobamovirus pathotype $P_{0}$ and $P_{1,2}$ was 61 ％ and 39％, respectively. All TMGMV isolates belonged to the pathotype $P_{0}$. In restriction enzyme analysis of the cDNAs synthesized with coat protein gene of PMMoV pathotype $P_{0}$ and $P_{1,2}$, the former had two TaqI sites but the later had one.one.