Fusion polypeptide comprising polypeptide region that can be O-glycosylated

A fusion polypeptide comprising the structure of the following formula:

• N′—(Z)n-Y—(Z)m-C′
• in the above formula,
• N′ is the N-terminus of the fusion polypeptide, C′ is the C-terminus of the fusion polypeptide,
• Y is a target polypeptide,
• Z is an O-glycosylatable polypeptide region,
• n is the number of O-glycosylatable polypeptide regions bound to the N-terminus of the target polypeptide, and is an integer of 1, and
• m is the number of O-glycosylatable polypeptide regions bound to the C-terminus of the target polypeptide, and is an integer of 2 or 3,
• wherein each of the O-glycosylatable polypeptide regions is independently selected from the group consisting of:
• (1) a hinge region of Immunoglobulin D (IgD),
• (2) a hinge region of Immunoglobulin A (IgA),
• (3) a polypeptide comprising the amino acid sequence of SEQ ID NO:
• 1,
• (4) a polypeptide comprising 5 or more consecutive amino acids of the amino acid sequence of SEQ ID NO:
• 1 and containing 3 to 7 O-glycosylated residues,
• (5) a polypeptide comprising 34 or more consecutive amino acids of Immunoglobulin D (IgD) and containing the polypeptide of (3) or (4),
• (6) a polypeptide comprising the amino acid sequence of SEQ ID NO:
• 2,
• (7) a polypeptide comprising 8 or more consecutive amino acids of the amino acid sequence of SEQ ID NO:
• 2 and containing 3 to 8 O-glycosylated residues, and
• (8) a polypeptide comprising 19 or more consecutive amino acids of Immunoglobulin A (IgA) and containing the polypeptide of (6) or (7),
• the fusion polypeptide is O-glycosylated, and
• the total number of O-glycans contained in the fusion polypeptide is 13 or more per the target polypeptide.