Patent ID: 7754208

Claim:
A fusion protein, comprising: (a) a binding domain polypeptide that binds CD20, wherein the binding domain comprises amino acids 23-265 of SEQ ID NO:397 except that leucine at position 155 of SEQ ID NO:397 is substituted with a serine, (b) a human IgG1 hinge peptide comprising a mutated core sequence as set forth in amino acids 279-282 of SEQ ID NO:397, 398 or 582, (c) an immunoglobulin heavy chain CH2 constant region polypeptide as set forth in amino acids 284-393 of SEQ ID NO:397 fused to the hinge peptide, (d) an immunoglobulin heavy chain CH3 constant region polypeptide as set forth in amino acids 39-500 of SEQ ID NO:397 fused to the CH2 polypeptide, and wherein the fusion protein promotes antibody dependent cell-mediated cytotoxicity, complement fixation, or both.