[期刊论文]

出版年：2003

Immunotoxins are genetically engineered fusion proteins of an antibody Fv fragment and a toxin from bacteria or plants, which function as anti-cancer therapeutics. Here, we describe a new generation of immunotoxins in which both proteins do not form a single fusion protein but are coupled specifically via cysteine-containing polyionic fusion peptides. The engineered Pseudomonas exotoxin PE38 was N-terminally fused to the peptide E8C. In combination with the disulfide-stabilized Fv fragment of the tumor-specific antibody B3, which was extended by the peptide R8CP, the fusion peptides ensured a specific and covalent coupling of the Fv fragment and the toxin. The resulting immunotoxin was as active and as specific as an immunotoxin consisting of a fusion protein of the same antibody fragment connected to the toxin.

Fv fragment;exotoxin;disulfide bond;polyionic peptides;FACS;B3(dsFv)PE38, genetically fused immunotoxin of the disulfide-stabilized Fv fragment of the antibody B3 and the Pseudomonas exotoxin derivative PE38;B3-PE38, conjugated immunotoxin composed of dsFv-B3-R8C and E8C-PE38;dsFv-B3-R8C, disulfide-stabilized Fv fragment of the antibody B3 extended at the C terminus of the VH domain by the peptide R8CP;GSH, reduced glutathione;GSSG, oxidized glutathione;PE38, truncated version of the Pseudomonas exotoxin consisting of a part of the domain Ib and domains II and III;GST, glutathione-S-transferase