| 摘要 |
PROBLEM TO BE SOLVED: To provide a new ligand bound molecule and a receptor and a composition and a method for improving the circulating plasma half-life of the ligand bound molecule. SOLUTION: This polypeptide contains a dimmer of immunoglobulin heavy chains without an immunoglobulin light chain. In the polypeptide, a variable domain of at least one of the immunoglobulin heavy chains is substituted with an amino acid sequence of a ligand binding partner that is a receptor, a carrier protein, a hormone, a growth factor, an enzyme or a nutrient substance and is not a lymphocyte homing receptor, a constituent element of an immunoglobulin gene superfamily, a protein homologous thereto or a multiple subunit polypeptide encoded with a discrete gene and the binding partner fuses to an amino acid sequence of an immunoglobulin constant domain at the C- terminus and holds binding characteristics. |
