ANTITUMOR PROTEIN HYBRID AND PROCESS FOR THE PREPARATION THEREOF

摘要

Antitumor protein hybrid, composed of a moiety which is substantially the fragment Fab of an antitumor immunoglobulin and a moiety which is substantially the fragment A of a diphtheria toxin, which is expressed by the following formula (I): Fab-S1-(X)n-S2-FA)m (I) (where Fab indicates a moiety which is substantially the fragment Fab of an antitumor immunoglobulin; FA indicates a moiety which is substantially the fragment A of a diphtheria toxin; X indicates a divalent organic radical; S1 and S2 are both sulfur atoms, S1 indicating a sulfur atom arising from the disulfide bond (-S-S- bond) in an immunoglobulin and S2 a sulfur atom arising from the disulfide bond in a diphtheria toxin; n stands for 0 to 1 and m stands for an integer of 1 to 5). This antitumor protein hybrid has remarkable and specific cytotoxicity against tumor cells, e.g., in mice.