title: A new approach in the synthesis of immunotoxins: ribosome inactivating protein noncovalently bound to monoclonal antibody.
abstract: This study describes the synthesis of a new generation of immunotoxins made by a noncovalent interaction between a monoclonal antibody derivatized with a dichlorotriazinic dye and the ribosomal inhibitor protein gelonin. The scheme of preparation has several advantages with respect to the traditional methods, which used heterobifunctional cross-linkers, such as a higher overall yield of production and the homogeneity of the obtained conjugate. Moreover, because no chemical derivatization of the gelonin was required, the unconjugated ribosome inactivating protein was recovered unaltered and therefore can be reused in other synthetic processes. This immunoconjugate was stable when tested in mouse serum and showed an interesting slow elimination rate when administered intravenously in mice. Although a high dye derivatization degree induced a modification of the specificity of the monoclonal antibody, the native specificity was restored after conjugation with gelonin. Furthermore the noncovalent linkage did not affect the gelonin inhibitory activity; in fact, the specific cytotoxic activity seemed to be similar to that of other disulfide-linked immunotoxins previously prepared in our laboratories.
authors.affiliation: Istituto di Chimica Farmaceutica Applicata, Torino, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Dosio
authors.forename: P
authors.initials: P
authors.lastname: Brusa
authors.forename: L
authors.initials: L
authors.lastname: Delprino
authors.forename: G
authors.initials: G
authors.lastname: Grosa
authors.forename: M
authors.initials: M
authors.lastname: Ceruti
authors.forename: L
authors.initials: L
authors.lastname: Cattel
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology; D000912:Antibodies, Neoplasm / Q000737:chemistry / Q000276:immunology; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000276:immunology; D002474:Cell-Free System; D002850:Chromatography, Gel; D004337:Drug Carriers; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D000922:Immunotoxins / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009363:Neoplasm Proteins / Q000096:biosynthesis; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology; D011500:Protein Synthesis Inhibitors / Q000737:chemistry* / Q000276:immunology; D054789:Ribosome Inactivating Proteins, Type 1; D014027:Tobacco Mosaic Virus / Q000187:drug effects / Q000378:metabolism; D014227:Triazines; D014407:Tumor Cells, Cultured; D014764:Viral Proteins / Q000096:biosynthesis
chemical_list: D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D004337:Drug Carriers; D000922:Immunotoxins; D009363:Neoplasm Proteins; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D054789:Ribosome Inactivating Proteins, Type 1; D014227:Triazines; D014764:Viral Proteins; C012842:Cibacron Blue F 3GA; C025674:GEL protein, Gelonium multiflorum