Conformational changes of Newcastle disease virus envelope glycoproteins triggered by gangliosides.
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.
Ferreira
Laura
L
Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Spain.
Villar
Enrique
E
Muñoz-Barroso
Isabel
I
D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002460:Cell Line; D005456:Fluorescent Dyes / Q000737:chemistry; D005732:Gangliosides / Q000494:pharmacology*; D006023:Glycoproteins / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009522:Newcastle disease virus / Q000737:chemistry*; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000187:drug effects*
D000817:Anilino Naphthalenesulfonates; D005456:Fluorescent Dyes; D005732:Gangliosides; D006023:Glycoproteins; D014759:Viral Envelope Proteins; C035763:5,5'-bis(8-(phenylamino)-1-naphthalenesulfonate)