• 대한바이러스학회지
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• 제27권1호
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• pp.9-17
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• 1997

Hepatitis C virus (HCV) E2 protein is known to be one of putative envelope proteins. To develop a sensitive detection method for HCV infected tissues and cells, monoclonal antibodys (MAbs) to the E2 protein of HCV were prepared from mice immunized with recombinant baculovirus-expressing E2 protein (Bac-E2). Several hybridoma clones secreting various levels of MAb were isolated and isotypes of these MAb were determined. One clone (L.2.3.3) was used for ascites production and the E2-MAb was purified and characterized. The L.2.3.3 reacted well with both Bac-E2 and E. coli expressed glutathione-S-transferase-E2 (GST-E2) fusion proteins. Using HCV patient sera, E2 envelope protein was found to be localized in the cell membrane boundary both in CHO cells and insect cells which express HCV E2 protein. Similar result was obtained when same cells were treated with the MAb L.2.3.3. These results demonstrated that Bac-E2 protein is capable of eliciting high titer antibody production in mice.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.97-101
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• 2001

The fusion between viral envelope and target cell membrane is a central step of viral infection, and the fusion proteins located at viral envelope mediate such process. Gp41 of HIV is one of the fusion proteins whose structure and mechanism of membrane fusion had been extensively studied. Functionally important motives of gp41 are the N-terminus fusion peptide, the coiled-coil and the membrane proximal C-peptide regions. The role of these regions during the fusion process had been thoroughly examined. Specially, insertion of the fusion peptide into membrane and conformational change of the coiled-coil and C-peptide regions are assumed to be critical for the fusion mechanism. In addition, the coiled-coil region has been shown to interact with membrane, and the C-peptide region regulates the interaction in a dose dependent manner. Furthermore, fusion defective mutations of the coiled-coil region dramatically changed its binding affinity to membrane. These results suggested that the membrane binding property of the coiled-coil region is important for the fusion activity of gp41, and such property could be modulated by the interaction with the C-peptide region.

• Journal of Microbiology
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• 제45권5호
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• pp.431-440
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• 2007

A silkworm (Bombyx mori L.) extract known to contain naturally occurring iminosugars, including 1-deoxynojirimycin (1-DNJ) derived from the mulberry tree (Morus alba L.), was evaluated in surrogate HCV and HBV in vitro assays. Antiviral activity of the silkworm extract and one of its purified constituents, 1-DNJ, was demonstrated against bovine viral diarrhea virus (BVDV) and GB virus-B (GBV-B), both members of the Flaviviridae family, and against woodchuck hepatitis virus (WHV) and hepatitis B virus (HBV), both members of the Hepadnaviridae family of viruses. The silkworm extract exhibited a 1,300 fold greater antiviral effect against BVDV in comparison to purified 1-DNJ. Glycoprotein processing of BVDV envelope proteins was disrupted upon treatment with the naturally derived components. The glycosylation of the WHV envelope proteins was affected largely by treatment with the silkworm extract than with purified 1-DNJ as well. The mechanism of action for this therapy may lie in the generation of defective particles that are unable to initiate the next cycle of infection as demonstrated by inhibition of GBV-B in vitro. We postulate that the five constituent iminosugars present in the silkworm extract contribute, in a synergistic manner, toward the antiviral effects observed for the inhibition of intact maturation of hepatitis viral particles and may complement conventional therapies. These results indicate that pre-clinical testing of the natural silkworm extract with regards to the efficacy of treatment against viral hepatitis infections can be evaluated in the respective animal models, in preparation for clinical trials in humans.

• Journal of Veterinary Science
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• 제21권1호
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• pp.5.1-5.12
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• 2020

The major glycoproteins of bovine gammaherpesvirus 4 (BoHV-4) are gB, gH, gM, gL, and gp180 with gB, gH, and gp180 being the most glycosylated. These glycoproteins participate in cell binding while some act as neutralization targets. Glycosylation of these envelope proteins may be involved in virion protection against neutralization by antibodies. In infected cattle, BoHV-4 induces an immune response characterized by low neutralizing antibody levels or an absence of such antibodies. Therefore, virus seroneutralization in vitro cannot always be easily demonstrated. The aim of this study was to evaluate the neutralizing capacity of 2 Argentine BoHV-4 strains and to associate those findings with the gene expression profiles of the major envelope glycoproteins. Expression of genes coding for the envelope glycoproteins occurred earlier in cells infected with isolate 10/154 than in cells infected with strain 07/435, demonstrating a distinct difference between the strains. Differences in serological response can be attributed to differences in the expression of antigenic proteins or to post-translational modifications that mask neutralizing epitopes. Strain 07/435 induced significantly high titers of neutralizing antibodies in several animal species in addition to bovines. The most relevant serological differences were observed in adult animals. This is the first comprehensive analysis of the expression kinetics of genes coding for BoHV-4 glycoproteins in 2 Argentine strains (genotypes 1 and 2). The results further elucidate the BoHV-4 life cycle and may also help determine the genetic variability of the strains circulating in Argentina.

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.171-176
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• 2012

HaCaT cells are the immortalized human keratinocytes and have been extensively used to study the epidermal homeostasis and its pathophysiology. T helper cells play a role in various chronic dermatological conditions and they can affect skin barrier homeostasis. To evaluate whether HaCaT cells can be used as a model cell system to study abnormal skin barrier development in various dermatologic diseases, we analyzed the gene expression profile of epidermal differentiation markers of HaCaT cells in response to major T helper (Th) cell cytokines, such as $IFN{\gamma}$, IL-4, IL-17A and IL-22. The gene transcriptional profile of cornified envelope-associated proteins, such as filaggrin, loricrin, involucrin and keratin 10 (KRT10), in HaCaT cells was generally different from that in normal human keratinocytes (NHKs). This suggests that HaCaT cells have a limitation as a model system to study the pathophysiological mechanism associated with the Th cell cytokine-dependent changes in cornified envelope-associated proteins which are essential for normal skin barrier development. In contrast, the gene transcription profile change of human ${\beta}2$-defensin (HBD2) in response to $IFN{\gamma}$, IL-4 or IL-17A in HaCaT cells was consistent with the expression pattern of NHKs. $IFN{\gamma}$ also up-regulated transglutaminase 2 (TGM2) gene transcription in both HaCaT cells and NHKs. As an alternative cell culture system for NHKs, HaCaT cells can be used to study molecular mechanisms associated with abnormal HBD2 and TGM2 expression in response to $IFN{\gamma}$, IL-4 or IL-17A.

• BMB Reports
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• 제38권1호
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• pp.65-70
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• 2005

Choristoneura fumiferana granulovirus (ChfuGV) infection results two types of enveloped virions: Occlusion-derived virus (ODV) and budded virus (BV). Structural proteins ODVP-6E/ODV-E56 and p74 are two major conserved ODV-associated proteins that may be involved in the initiation of viral infection cycle in susceptible host insect larvae. This study presents the characterization of ChfuGV odvp-6e/odv-e56 and p74 transcription and translation as well as immunolocalization of these proteins in the occluded ChfuGV virion. Our results revealed that the transcription of odvp-6e/odv-e56 and p74 genes, both, start at 24 hours post infection (h p.i.). Using monospecific polyclonal antibodies made against ODVP-6E/ODV-E56 and p74 we demonstrated that these proteins are both expressed late in infection (24 h p.i.). Immunogold labeling using antisera against ODVP-6E/ODV-E56 and p74 proteins demonstrated that ODVP-6E/ODV-E56 and p74 proteins are both associated with the ODV envelop of ChfuGV.

• 한국축산식품학회지
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• 제37권1호
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• pp.134-138
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• 2017

Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (${\underline{s}}pheroplast$ ${\underline{p}}rotein$ ${\underline{y}}$). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella.

• Genomics & Informatics
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• 제19권4호
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• pp.48.1-48.10
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• 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encodes small envelope protein (E) that plays a major role in viral assembly, release, pathogenesis, and host inflammation. Previous studies demonstrated that pyrazine ring containing amiloride analogs inhibit this protein in different types of coronavirus including SARS-CoV-1 small envelope protein E (SARS-CoV-1 E). SARS-CoV-1 E has 93.42% sequence identity with SARS-CoV-2 E and shared a conserved domain NS3/small envelope protein (NS3_envE). Amiloride analog hexamethylene amiloride (HMA) can inhibit SARS-CoV-1 E. Therefore, we performed molecular docking and dynamics simulations to explore whether amiloride analogs are effective in inhibiting SARS-CoV-2 E. To do so, SARS-CoV-1 E and SARS-CoV-2 E proteins were taken as receptors while HMA and 3-amino-5-(azepan-1-yl)-N-(diaminomethylidene)-6-pyrimidin-5-ylpyrazine-2-carboxamide (3A5NP2C) were selected as ligands. Molecular docking simulation showed higher binding affinity scores of HMA and 3A5NP2C for SARS-CoV-2 E than SARS-CoV-1 E. Moreover, HMA and 3A5NP2C engaged more amino acids in SARS-CoV-2 E. Molecular dynamics simulation for 1 ㎲ (1,000 ns) revealed that these ligands could alter the native structure of the proteins and their flexibility. Our study suggests that suitable amiloride analogs might yield a prospective drug against coronavirus disease 2019.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.421-424
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• 2005

Effect of antibiotics belonging to three different groups, including third generation cephalosporins, aminoglycosides, and quinolones, on the outer membrane protein (OMP) profile of Klebsiella pneumoniae was examined. It was found that a new OMP (porins) of 40 kDa molecular mass was expressed in Klebsiella pneumoniae, when grown in the presence of ceftazidime, whereas new proteins with 30 kDa and 22 kDa masses were detected in the presence of ofloxacin. The immunoblot analysis showed that the new proteins of 40 kDa and 30 kDa molecular masses were expressed on the outer envelope, when being exposed to antibiotics ceftazidime and ofloxacin, respectively. This finding is important, as the outer surface comes in contact with the immune system, and therefore may have a bearing on the outcome of the disease.

• BMB Reports
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• 제29권2호
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• pp.180-182
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• 1996

One of the essential functions of virus surface proteins is the recognition of specific receptors on target cell membranes, and cellular receptors play an important role in viral pathogenesis. But the earliest steps of hepatitis B virus (HBV) infection, such as hepatocyte receptor interaction with the virus, are poorly understood. Previous work has suggested an important role of the preS1 region of HBV envelope protein in mediating viral binding to hepatocytes. Although hepatitis B virus (HBV) infection appears to be initiated by specific binding of virions to cell membrane structures via one or potentially several viral surface proteins, data showing the identification or isolation of the HBV receptor (s) are not yet available. The receptor-like proteins on the plasma membrane surface of HepG2 cells that bind to PreS1 were separated and identified using affinity chromatography, and the amino-terminal amino acid sequences of the receptor-like proteins were determined.