Production in Escherichia coli of a functional murine and murine::human chimeric F(ab')2 fragment and mature antibody directed against human placental alkaline phosphatase.

We report the production in Escherichia coli of a murine antibody IgG2b, a murine::human chimeric antibody IgG3 and the corresponding F(ab')2 fragments, all directed against human placental alkaline phosphatase, a tumor marker. The cDNA of the heavy chain of the mature antibodies and their fragments were linked up to the bacterial alkaline phosphatase signal sequence and were placed under control of the inducible tac promoter. Coexpression with the murine kappa light chain resulted in production of functional dimeric, trimeric and tetrameric, mature antibodies and F(ab')2 fragments in the periplasm of E. coli in a yield of 200-300 micrograms l-1. High amounts of light and heavy chains were present also in the insoluble fraction.