PROTEIN HAVING AFFINITY FOR IMMUNOGLOBULIN, AND IMMUNOGLOBULIN-BINDING AFFINITY LIGAND

摘要

An object of the present invention is to create a novel engineered Protein A ligand having better antibody dissociation properties in the presence of an acid than conventional engineered Protein A ligands and a further object of the present invention is to create a novel engineered Protein A ligand having higher alkali resistance. The present invention is to provide a protein having an affinity for an immunoglobulin, including an amino acid sequence derived from any of E, D, A, B and C domains of Protein A, wherein at least one Gly residue in the amino acid sequence is replaced with an amino acid other than Ala, and the protein has a lower affinity for an Fab region of an immunoglobulin than a protein including an amino acid sequence in which the Gly residue is replaced with Ala. Also, the present invention is to provide the protein having an affinity for an immunoglobulin, which has improved chemical stability in an alkaline condition compared to the corresponding domain.