| abstract |
An object of the present invention is to provide a technique to create novel engineered protein ligands that, when immobilized through a lysine residue (its side chain ε-amino group) which allows for efficient immobilization to a carrier, show the optimum binding capacity and binding efficiency to a target molecule. The present invention provides an engineered protein having a sequence obtained by replacing all the lysine residues in Protein A, which is the most typical protein ligand, with other amino acids, and adding lysine at a terminal; and an affinity separation matrix in which such an engineered protein is immobilized on a water-insoluble carrier by reductive amination or the like. This affinity separation matrix is characterized by its high binding capacity to a target molecule even when the immobilized amount of the ligand is small. |