Toxic type II ribosome-inactivating protein (RIP). Induces apoptosis. Has cytotoxic activity against several human cancer cell lines. Is less cytotoxic to normal human cells. Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA. Disulfide-linked dimer of A and B chains. Glycosylated. The inhibitory concentration 50% (IC50) is 0.8 ng/ml for transformed cells and 10 ng/ml for normal cells. Belongs to the ribosome-inactivating protein family. Type 2 RIP subfamily.