Change the method for isoelectric point of antibody using the amino acid substitution of CDR

The inventors of the present invention provide: can be exposed to the charge of at least one amino acid residue on the surface complementarity-determining region (CDR) by changing, change the method for the isoelectric point of antibody while keeping the antigen-binding activity of antibody.The present invention also provides the method for purifying multi-specificity antibody by changing isoelectric point and by changing the dynamic (dynamical) method of drug in blood plasma of the isoelectric point to improve antibody.Also, the present invention provides the antibody that isoelectric point is changed, the medical composition and its manufacturing method that contain the antibody as effective component.