| abstract |
The present invention relates to immunoglobulin-binding proteins in which one or more asparagine residues are mutated to amino acids other than glutamine or aspartic acid, which mutations give increased chemical stability at pHs of about 13-14 or less relative to the parent molecule. It is about. This protein may be derived, for example, from a B-domain of a protein capable of binding other regions of the immunoglobulin molecule, rather than complementarity determining regions (CDRs) such as Protein A and preferably Staphylococcus protein A . The present invention also relates to a matrix for affinity separation comprising a immunoglobulin-binding protein in which at least one asparakinic residue is mutated to an amino acid other than glutamine, as a ligand bound to a solid support. |