Patent ID: 8252901

Claim:
A membrane fusion protein having an isoelectric point of at least about 7 comprising an amino acid sequence which is at least 50% similar to the sequence defined by SEQ ID NO: 2, wherein said amino acid sequence comprises an N-terminal myristylation consensus sequence defined by SEQ ID NO: 9 after the initiation methionine, wherein X 2 , X 3 , X 4 , X 5 , and X 6 of SEQ ID NO: 9 are small uncharged residues and X 6 is not proline; a transmembrane domain; at least one positive cluster comprising at least three positively charged amino acid residues within a contiguous sequence of about 25 residues, wherein the contiguous sequence is within about 100 residues flanking the transmembrane domain at the C-terminal side; and at least one polyproline motif comprising at least 3 contiguous proline residues within the residues flanking the transmembrane domain at the C-terminal side.