Antitumor protein hybrid and process for the preparation thereof

Abstract

Antitumor protein hybrid, having a moiety consisting of the antitumor immunoglobulin and a moiety substantially consisting of the fragment A of a diphtheria toxin, which is expressed by the following formula (I): Ab(NHCO--X--S.sub.1 --S.sub.2 --FA).sub.n (I) (where Ab indicates a moiety consisting of the antitumor immunoglobulin and FA indicates a moiety substantially consisting of the fragment A of a diphtheria toxin; X is an alkylene group or phenylene group which either has or does not have a branching of 1 to 5 carbon atoms. N in the amido bond is a nitrogen atom arising from the amino group in the antitumor immunoglobulin; S.sub.1 and S.sub.2 are both sulfur atoms, S.sub.2 indicating a sulfur atom arising from the disulfide bond in a diphtheria toxin; n stands for an integer of 1 to 5). This antitumor protein hybrid has remarkable and specific citotoxicity against tumor cells.

Dependencies are inferred from the claim text.