| abstract |
The invention discloses a polypeptide with improved alkaline stability, which polypeptide comprises a mutant of a B or C domain of Staphylococcus Protein A (SpA), as specified by SEQ ID NO 1 or SEQ ID NO 2, or of Protein Z, as specified by SEQ ID NO 3, wherein at least the glutamic acid residue at position 15 has been mutated to an amino acid other than asparagine. The invention also discloses multimers of said polypeptide, as well as separation matrices comprising the multimers or polypeptides. |