The invention relates to the technical field of
biology, in particular to a polypeptide, a preparation method of the polypeptide, a
bispecific antibody and application of the
bispecific antibody. The polypeptide is an
Fc binding polypeptide, and can be universally, simply and conveniently connected with a
monoclonal antibody to prepare a bispecific / multispecific
antibody. The polyvalent
Fc binding polypeptide PGLU-Fc-III-4C or PASP-Fc-III-4C is prepared by bonding side carboxyl groups of
polyglutamic acid (PGLU) or
polyaspartic acid (PASP) with Fc-III-4C polypeptide which has general high affinity to an immune
globulin (
antibody)
constant region (Fc), and the polyvalent
Fc binding polypeptide can react with various
monoclonal antibodies in different proportions in an
aqueous solution to obtain a bispecific / multispecific antibody. The preparation method of the bispecific / multispecific antibody has the following advantages: the bispecific / multispecific antibody is prepared by direct incubation in a
water environment, the reaction condition is mild, and the activity of the
monoclonal antibody can be retained to the greatest extent; and the method is simple, efficient, controllable in
monoclonal antibody proportion and high in universality, and has an industrialization prospect.