Patent ID: 7150872

Claim:
A polyalkylene oxide single-chain antigen-binding polypeptide conjugate, comprising a polyalkylene oxide conjugated to at least one single-chain antigen-binding polypeptide, wherein the single-chain antigen-binding polypeptide is monovalent or multivalent and wherein the single-chain antigen-binding polypeptide comprises, (a) a first polypeptide comprising an antigen binding portion of a variable region of an antibody heavy or light chain; (b) a second polypeptide comprising an antigen binding portion of a variable region of an antibody heavy or light chain; and (c) a peptide linker linking the first and second polypeptides, wherein the single-chain antigen-binding polypeptide has at least three consecutive Lys residues, and that has an antigen binding site, and wherein any one of the consecutive Lys residues is located at a position selected from the group consisting of: (i) the amino acid position 11, 12, 13, 14 or 15 of the light chain variable region; (ii) the amino acid position 77, 78 or 79 of the light chain variable region; (iii) the amino acid position 11, 12, 13, 14 or 15 of the heavy chain variable region; (iv) the amino acid position 82B, 82C or 83 of the heavy chain variable region; (v) any amino acid position of the peptide linker; (vi) adjacent to the C-terminus of the first or second polypeptide; and (vii) combinations thereof; and wherein the polyalkylene oxide is conjugated to one of the consecutive Lys residues.