Important amino acid in the hemagglutinin glycoprotein of measles virus (MV) that governs hemadsorption

Two strains of measles virus IMA and SMD that were isdated using B95a cell line show hemadsorption negative. After adaptation to Vero cells, these strains gain the ability to agglutinate AGM-RBC and show hemadsorption positive. Sequence analysis of these two kinds of virus reveals that the two strains all have a Ser (HAD negative) to Gly (HAD positive) mutation at position 546 in the H protein. Site-directed mutagenesis and expression in COS cells were used to confirm that the mutation Ser→Gly is responsible for hemadsorption alteration. Then the monoclonal antibody against CD46 was used to identify that this mutation also governs the binding function of MV H protein to CD46 receptor. The data provide a new important amino acid of MV H protein that governs the hemadsorption and binding to CD46 receptor.