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 immunogloblin and a moiety which is the subunit A of ricin, which is expressed by the following formula (I): Fab?S1-(X)n-S2-RA)m ..................(I) (where Fab indicates a moiety which is substantially the fragment Fab of an antitumor immunogloblin; RA indicates a moiety which is the subunit A of ricin; 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 ricin; n stands for 0 or 1 and m stands for an integer of 1 to 5). This antitumor protein hybrid has remarkable and specific cytotoxicity against tumor cells.