| abstract |
Immunotoxins formed by the covalent coupling of, on the one hand, the A chain of ricin, as such or correctly modified, with, on the other hand, an antibody or a fragment of an antibody, used in its natural form or correctly modified, which possesses the capacity to selectively recognize an antigen carried by the intended target cells. The coupling is effected either via a disulfide bond or via a thioether bond, with the limitation that, when the coupling is effected via a disulfide and one of the sulfur atoms is that belonging to the A chain of ricin, the other sulfur is bonded to the antibody by a spacing structure which is itself bonded to a group of the protein other than an amine group. |