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

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