| abstract |
The present invention addresses the problem of providing a protein that exhibits resistance to serine protease or thermolysin, has an activity to bind to immunoglobulin and is appropriately usable as an affinity ligand. According to one embodiment of the present invention, provided is: a protein having an affinity to immunoglobulin, said protein having at least two domains derived from any of the amino acid sequences of E, D and A domains of protein A, wherein at least one amino acid sequence of these domains contains one or more lysine residues and lysine at the C-terminus is deleted or substituted; or a protein having an affinity to immunoglobulin, said protein having at least two domains derived from any of B, C and Z domains of protein A, wherein at least one amino acid sequence of these domains contains one or more lysine residues and lysine at the 4-position and lysine at the C-terminus are deleted or substituted. |