Effect of Proteolytic Cleavage on the Conformation of the Newcastle Disease Virus (NDV) Main Structural Glycoprotein
| Autor: | L. Wassilewa, Y. Abashev, V. Neitchev, L. Doumanova |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Biotechnology & Biotechnological Equipment. 19:3-5 |
| ISSN: | 1314-3530 1310-2818 |
| Popis: | structural NDV glycoproteins, the haemagglutinin-neuraminidase (HN) and the fu- sion protein (F) of La Sola strain of NDV were isolated from the pure virions by octyl glu- coside disruption, followed by ultracentifuge separation and chromatograhy on DEAE Bio gel column. Protein conformations measured by circular dichroism (CD) spectra (re- corded using Jasko-J-500 A spectropolarimeter) were expressed as the percentage of a- helix and random coil on the base of mean ellipticity (θ). The HN NDV-glycoprotein has haemagglutinating and neuraminidase activities and it is responsible for the attachment of the virus to the cell surface, the penetration and the release of the virions from the cells. This gly- coprotein possesses one polypeptide chain and its secondary structure is represented by 15% a- helix and 85% random coil. The other glycoprotein, the F-protein, plays an essential role in the entry of virus into the cell by fusion of the viral envelope with the cell membrane. The active F- protein is presented in the infected cells as a disulfide-linked complex of two glycopeptides F1 and F2 derived from a precursor Fo by proteolytic cleavage. The active cleaved F-protein con- sists of 31% a-helix and 69% random coil. The treatment of pure HN with proteolytic enzymes enhances twice the activity of the protein and changes the conformation by increase of the a-he- lix percentage, i.e. 38% and diminishment of random coil to 62%. In conclusion, the proteolytic cleavage of NDV-glyco-proteins, essential for their biological activities, is connected with changes of their conformation. |
| Databáze: | OpenAIRE |
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