Patent ID: 8372950

Claim:
A human IgG binding peptide tag that is 11 to 16 amino acids in length, comprising at least an amino acid sequence of formula I: C-(X) n -W-X-X-X-W-(X) m -C (I) (SEQ ID NO: 17) wherein n and m are each an integer of 1 or more and the sum n+m is 4 or 5, wherein X-X-X in the formula I contains no cysteine residue, and wherein said amino acid sequence satisfies either or both of a) and b): a) (X) n -W in the formula I is Za-G-Y-W (SEQ ID NO: 18); and b) W-(X) m in the formula I is W-G-L-Zb (SEQ ID NO: 19) wherein Za and Zb are each 0, 1, or more amino acid residues.