Patent ID: 8906386

Claim:
A mutant protein, the amino acid sequence of which comprises a sequence which is derivable from that of the wild-type F protein of a PIV-5 virus: by replacement of the amino acid which, in the sequence of said wild-type PIV-5 F protein, is in position 22; and of the amino acid which, in the sequence of said wild-type PIV-5 F protein, is in position 132; and of the amino acid which, in the sequence of said wild-type PIV-5 F protein, is in position 290; and of the amino acid which, in the sequence of said wild-type PIV-5 F protein, is in position 447; and by replacement: of the amino acid which, in the sequence of said wild-type PIV-5 F protein, is in position 147, by a hydrophobic amino acid selected from V, I, L, preferably V; and/or of the amino acid which, in the sequence of said wild-type PIV-5 F protein, is in position 158 by a hydrophobic amino acid selected from V, I, L, preferably V; wherein said positions are computed by alignment with respect to the reference wild-type PIV-5 F protein of SEQ ID NO: 31.