NOVEL MODIFIED PROTEIN OF EXTRACELLULAR DOMAIN OF PROTEIN G

摘要

The purpose of the present invention is to provide a novel protein, or the like, which has reduced bindability with the Fc region and/or the Fab region of an immunoglobulin in a weakly acidic range and has an elution pH which has been shifted towards weak acidity. The present invention pertains to: a protein that has a binding activity to the Fc region of immunoglobulin G and, as a result of substituting a residue in the vicinity of a positively charged residue of protein G for the positively charged residue, has a reduced binding activity to the Fc region of immunoglobulin G in a weakly acidic range compared to a protein comprising a wild-type protein G B domain; a scavenger of immunoglobulin G or of a protein having the Fc region or the Fab region of immunoglobulin G, wherein the protein is immobilised on a water-insoluble solid-phase support; affinity chromatography for purification of immunoglobulin G or of a protein having the Fc region or the Fab region of immunoglobulin G, said affinity chromatography including the scavenger; and a method which uses the affinity chromatography for purification and in which immunoglobulin G or a protein having the Fc region or the Fab region of immunoglobulin G is purified.