tailieunhanh - Báo cáo khóa học: Conformational changes of Newcastle disease virus envelope glycoproteins triggered by gangliosides

We have investigated the conformational changes of New-castle disease virus (NDV) glycoproteins in response to receptor binding, using 1,1-bis(4-anilino)naphthalene-5,5-disulfonic acid (bis-ANS) as a hydrophobicity-sensitive probe. Temperature- and pH-dependent conformational changes were detected in the presence of free bovine gan-gliosides. The fluorescence of bis-ANS was maximal at pH 5. The binding of bis-ANS to NDV was not affected by chemicals that denature the fusion glycoprotein, such as reducing agents, nor by the presence of neuraminidase inhibitors such as N-acetyl neuramicic acid | Eur. J. Biochem. 271 581-588 2004 FEBS 2004 doi Conformational changes of Newcastle disease virus envelope glycoproteins triggered by gangliosides Laura Ferreira Enrique Villar and Isabel Munoz-Barroso Departamento de Bioquimica y Biologia Molecular Universidad de Salamanca Spain We have investigated the conformational changes of Newcastle disease virus NDV glycoproteins in response to receptor binding using 1 1-bis 4-anilino naphthalene-5 5-disulfonic acid bis-ANS as a hydrophobicity-sensitive probe. Temperature- and pH-dependent conformational changes were detected in the presence of free bovine gangliosides. The fluorescence of bis-ANS was maximal at pH 5. The binding of bis-ANS to NDV was not affected by chemicals that denature the fusion glycoprotein such as reducing agents nor by the presence of neuraminidase inhibitors such as N-acetyl neuramicic acid. Gangliosides partially inhibited fusion and hemadsorption but not neuraminidase hemagglutinin-neuraminidase glycoprotein HN activity. A conformational intermediate of HN triggered by the presence of gangliosides acting as receptor mimics was detected. Our results indicate that upon binding to free gangliosides HN undergoes a certain conformational change that does not affect the fusion glycoprotein. Keywords NDV bis-ANS conformational intermediates paramyxovirus receptors gangliosides. Newcastle disease virus NDV is an avian enveloped virus belonging to the family of Paramyxoviridae genus Avulavirus. The membrane contains two transmembrane glycoproteins hemagglutin-neuraminidase HN and the fusion F protein 1 . HN binds to sialic acid-containing receptors at the cell surface through its hemagglutinating activity receptor-binding activity and it also displays neuraminidase or sialidase activity receptor-destroying activity which probably prevents the aggregation of the viral progeny. In addition a third activity the so-called fusion promotion activity has been proposed for the HN