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Structural characteristics and antiviral activity of multiple peptides derived from MDV glycoproteins B and H.

Wang X, Chi X, Wang M - Virol. J. (2011)

Bottom Line: These peptides were also significantly able to reduce lesion formation on chorioallantoic membranes (CAMs) of infected chicken embryos at a concentration of 0.5 mM in 60 μl of solution.None of the peptides exhibited cytotoxic effects at the concentrations tested.The present study examining the antiviral activity of these MDV peptides, which are useful as small-molecule antiviral inhibitors, provides information about the MDV entry mechanism.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No, 2, Yuan Ming Yuan West Road, Haidian District, Beijing 100193, PR China. wangxj@cau.edu.cn

ABSTRACT

Background: Marek's disease virus (MDV), which is widely considered to be a natural model of virus-induced lymphoma, has the potential to cause tremendous losses in the poultry industry. To investigate the structural basis of MDV membrane fusion and to identify new viral targets for inhibition, we examined the domains of the MDV glycoproteins gH and gB.

Results: Four peptides derived from the MDV glycoprotein gH (gHH1, gHH2, gHH3, and gHH5) and one peptide derived from gB (gBH1) could efficiently inhibit plaque formation in primary chicken embryo fibroblast cells (CEFs) with 50% inhibitory concentrations (IC50) of below 12 μM. These peptides were also significantly able to reduce lesion formation on chorioallantoic membranes (CAMs) of infected chicken embryos at a concentration of 0.5 mM in 60 μl of solution. The HR2 peptide from Newcastle disease virus (NDVHR2) exerted effects on MDV specifically at the stage of virus entry (i.e., in a cell pre-treatment assay and an embryo co-treatment assay), suggesting cross-inhibitory effects of NDV HR2 on MDV infection. None of the peptides exhibited cytotoxic effects at the concentrations tested. Structural characteristics of the five peptides were examined further.

Conclusions: The five MDV-derived peptides demonstrated potent antiviral activity, not only in plaque formation assays in vitro, but also in lesion formation assays in vivo. The present study examining the antiviral activity of these MDV peptides, which are useful as small-molecule antiviral inhibitors, provides information about the MDV entry mechanism.

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GF results and structural analyses of five peptides. (top) GF analysis of peptides. The purified peptides were loaded onto the Superdex G75 column in a buffer solution of 20 mM Tris-HCl, pH 8.0. The peak molecular mass was estimated by comparison with the protein standards running on the same column. The clear peak of gHH1 occurred at about 12.1 kDa. This molecular mass matches the approximate sum of four molecules, indicating the formation of the homotetrameric structure. The peak of gHH2 occurred at about 7.2 kDa, indicating the formation of the homodimeric structure. The peak of gHH3 occurred at about 3.8 kDa, indicating the monomeric state. The peak of gHH5 occurred at about 9.1 kDa, indicating the formation of the homotrimeric structure. The peak of gBH1 occurred at about 10.7 kDa, indicating the formation of the homotrimeric structure. (bottom) Sequences and calculated oligomeric states of gHH1, gHH2, gHH3, gHH5, and gBH1 in aqueous solution.
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Figure 5: GF results and structural analyses of five peptides. (top) GF analysis of peptides. The purified peptides were loaded onto the Superdex G75 column in a buffer solution of 20 mM Tris-HCl, pH 8.0. The peak molecular mass was estimated by comparison with the protein standards running on the same column. The clear peak of gHH1 occurred at about 12.1 kDa. This molecular mass matches the approximate sum of four molecules, indicating the formation of the homotetrameric structure. The peak of gHH2 occurred at about 7.2 kDa, indicating the formation of the homodimeric structure. The peak of gHH3 occurred at about 3.8 kDa, indicating the monomeric state. The peak of gHH5 occurred at about 9.1 kDa, indicating the formation of the homotrimeric structure. The peak of gBH1 occurred at about 10.7 kDa, indicating the formation of the homotrimeric structure. (bottom) Sequences and calculated oligomeric states of gHH1, gHH2, gHH3, gHH5, and gBH1 in aqueous solution.

Mentions: The structural characteristics of the five peptides that demonstrated protective effects in the cell and embryo infectivity assays were examined. Firstly, MS spectrometry showed that the molecular masses of gHH1, gHH2, gHH3, gHH5, and gBH1 were 3184, 3623, 3795, 3002 and 3303 Da, respectively. To investigate the structures of these peptides, gel filtration (GF) and circular dichroism (CD) spectroscopy analyses were performed. These results demonstrated that the majority of the peptides transitioned to the oligomeric state in the polar environments of Tris-HCl and lipidic solutions with 2,2,2 trifluoroethanol (TFE). Specifically, GF chromatography of gHH2 demonstrated the formation of a homodimeric structure with a molecular mass of about 7.2 kDa in aqueous solution. CD spectroscopy of gHH2 showed that the peptide adopts a β-sheet conformation in aqueous solution, and this tendency towards β-sheet formation becomes more obvious in a TFE solution. GF chromatography of gHH5 revealed a molecular mass of 9.1 kDa, suggesting the formation of a homotrimeric structure in polar environments. Analysis of gHH5 revealed a conformational change from a random coiled structure to a more obvious α-helical structure when the peptide was transferred from a polar environment to membrane interfaces using aqueous mixtures of TFE, suggesting the formation of potential higher-order oligomers in lipidic solutions. These results are presented in Figures 5 and 6.


Structural characteristics and antiviral activity of multiple peptides derived from MDV glycoproteins B and H.

Wang X, Chi X, Wang M - Virol. J. (2011)

GF results and structural analyses of five peptides. (top) GF analysis of peptides. The purified peptides were loaded onto the Superdex G75 column in a buffer solution of 20 mM Tris-HCl, pH 8.0. The peak molecular mass was estimated by comparison with the protein standards running on the same column. The clear peak of gHH1 occurred at about 12.1 kDa. This molecular mass matches the approximate sum of four molecules, indicating the formation of the homotetrameric structure. The peak of gHH2 occurred at about 7.2 kDa, indicating the formation of the homodimeric structure. The peak of gHH3 occurred at about 3.8 kDa, indicating the monomeric state. The peak of gHH5 occurred at about 9.1 kDa, indicating the formation of the homotrimeric structure. The peak of gBH1 occurred at about 10.7 kDa, indicating the formation of the homotrimeric structure. (bottom) Sequences and calculated oligomeric states of gHH1, gHH2, gHH3, gHH5, and gBH1 in aqueous solution.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3113977&req=5

Figure 5: GF results and structural analyses of five peptides. (top) GF analysis of peptides. The purified peptides were loaded onto the Superdex G75 column in a buffer solution of 20 mM Tris-HCl, pH 8.0. The peak molecular mass was estimated by comparison with the protein standards running on the same column. The clear peak of gHH1 occurred at about 12.1 kDa. This molecular mass matches the approximate sum of four molecules, indicating the formation of the homotetrameric structure. The peak of gHH2 occurred at about 7.2 kDa, indicating the formation of the homodimeric structure. The peak of gHH3 occurred at about 3.8 kDa, indicating the monomeric state. The peak of gHH5 occurred at about 9.1 kDa, indicating the formation of the homotrimeric structure. The peak of gBH1 occurred at about 10.7 kDa, indicating the formation of the homotrimeric structure. (bottom) Sequences and calculated oligomeric states of gHH1, gHH2, gHH3, gHH5, and gBH1 in aqueous solution.
Mentions: The structural characteristics of the five peptides that demonstrated protective effects in the cell and embryo infectivity assays were examined. Firstly, MS spectrometry showed that the molecular masses of gHH1, gHH2, gHH3, gHH5, and gBH1 were 3184, 3623, 3795, 3002 and 3303 Da, respectively. To investigate the structures of these peptides, gel filtration (GF) and circular dichroism (CD) spectroscopy analyses were performed. These results demonstrated that the majority of the peptides transitioned to the oligomeric state in the polar environments of Tris-HCl and lipidic solutions with 2,2,2 trifluoroethanol (TFE). Specifically, GF chromatography of gHH2 demonstrated the formation of a homodimeric structure with a molecular mass of about 7.2 kDa in aqueous solution. CD spectroscopy of gHH2 showed that the peptide adopts a β-sheet conformation in aqueous solution, and this tendency towards β-sheet formation becomes more obvious in a TFE solution. GF chromatography of gHH5 revealed a molecular mass of 9.1 kDa, suggesting the formation of a homotrimeric structure in polar environments. Analysis of gHH5 revealed a conformational change from a random coiled structure to a more obvious α-helical structure when the peptide was transferred from a polar environment to membrane interfaces using aqueous mixtures of TFE, suggesting the formation of potential higher-order oligomers in lipidic solutions. These results are presented in Figures 5 and 6.

Bottom Line: These peptides were also significantly able to reduce lesion formation on chorioallantoic membranes (CAMs) of infected chicken embryos at a concentration of 0.5 mM in 60 μl of solution.None of the peptides exhibited cytotoxic effects at the concentrations tested.The present study examining the antiviral activity of these MDV peptides, which are useful as small-molecule antiviral inhibitors, provides information about the MDV entry mechanism.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No, 2, Yuan Ming Yuan West Road, Haidian District, Beijing 100193, PR China. wangxj@cau.edu.cn

ABSTRACT

Background: Marek's disease virus (MDV), which is widely considered to be a natural model of virus-induced lymphoma, has the potential to cause tremendous losses in the poultry industry. To investigate the structural basis of MDV membrane fusion and to identify new viral targets for inhibition, we examined the domains of the MDV glycoproteins gH and gB.

Results: Four peptides derived from the MDV glycoprotein gH (gHH1, gHH2, gHH3, and gHH5) and one peptide derived from gB (gBH1) could efficiently inhibit plaque formation in primary chicken embryo fibroblast cells (CEFs) with 50% inhibitory concentrations (IC50) of below 12 μM. These peptides were also significantly able to reduce lesion formation on chorioallantoic membranes (CAMs) of infected chicken embryos at a concentration of 0.5 mM in 60 μl of solution. The HR2 peptide from Newcastle disease virus (NDVHR2) exerted effects on MDV specifically at the stage of virus entry (i.e., in a cell pre-treatment assay and an embryo co-treatment assay), suggesting cross-inhibitory effects of NDV HR2 on MDV infection. None of the peptides exhibited cytotoxic effects at the concentrations tested. Structural characteristics of the five peptides were examined further.

Conclusions: The five MDV-derived peptides demonstrated potent antiviral activity, not only in plaque formation assays in vitro, but also in lesion formation assays in vivo. The present study examining the antiviral activity of these MDV peptides, which are useful as small-molecule antiviral inhibitors, provides information about the MDV entry mechanism.

Show MeSH
Related in: MedlinePlus