The invention provides a
bifunctional antibody and a construction method thereof. The
bifunctional antibody comprises an
antibody heavy chain constant area, an antibody light chain constant area, a first
target protein, which is connected to the antibody
heavy chain constant area, and a second
target protein, which is connected to the antibody light chain constant area. The construction method of the
bifunctional antibody comprises the following steps: individually obtaining the antibody
heavy chain constant area
gene, antibody light chain constant area
gene, the first
target gene, and the second
target gene; adopting expression carriers to construct recombinant carrier shuttle plasmids of the genes mentioned above; transfecting the recombinant carrier shuttle plasmids to an expression bacterium strain to carry out culture so as to obtain the bifunctional antibody; carrying out
centrifugation, and collecting the supernate or purifying the cells so as to obtain the bifunctional antibody. The construction method assembles antibody molecules in a
gene level, thus the pertinence is strong, and the method is easy to achieve. The obtain bifunctional antibody comprises two
antigen combining sites, so the bifunctional antibody can combine two different antigens at the same time.