To provide methods for stably producing an
antibody enzyme excellent in storage stability.SOLUTION: There is disclosed a method for producing a κ light chain
antibody comprising the steps of: expressing a κ light chain
antibody in an
intracellular or
extracellular expression
system by using an
expression vector comprising a
polynucleotide that encodes the κ light chain antibody; subjecting the expressed product to
column chromatography using a column containing a first filler to obtain a crude product containing the κ light chain antibody; adding
metal ions to the crude product containing the κ light chain antibody so as to obtain a crudely purified product containing a complex of κ light chain antibody with the
metal ions; purifying the crudely purified product containing the κ light chain antibody-
metal complex by
column chromatography using a column containing a second filler from the crudely purified product containing the complex of the κ light chain antibody, to obtain a purified κ light chain antibody-metal complex; and removing the metal ions from the purified κ light chain antibody-metal complex so as to obtain a purified product of the κ light chain antibody.SELECTED DRAWING: None