RECOMBINANT IMMUNOTOXIN COMPOSED OF A SINGLE CHAIN ANTIBODY REACTING WITH THE HUMAN TRANSFERRIN RECEPTOR AND DIPHTHERIA TOXIN

摘要

Single chain immunotoxins directed at the human transferrin receptor, according to methods based on the enzymatic amplification of the genome. The anti-TFR (Fv) -PE40 contains DNA for the part of antigen binding (Fv) of a monoclonal antibody which targets the receptor of human transferrin fused to DNA for a molecular weight of fragment 40000 of Pseudomonas exotoxin (PE40). In another fused protein, DT388-anti-TFR (Fv) DNA for antigen binding portions of the anti-TFR antibody was fused to the DNA encoding a truncated form of diphtheria toxin. In the anti-TFR (Fv) -PE40, the single chain antibody precedes the toxin, while in the DT388-anti-TFR (Fv), the single chain antibody is located at the carboxyl terminus of the toxin. The proteins encoded by these gene fusions were expressed in E. coli and purified to homogeneity almost perfect by conventional chromatographic techniques.