GalNAc-specific agglutinin. Behaves as a type-2 ribosome-inactivating protein. Inhibits mammalian ribosomes (PubMed:10785398). The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA (Probable). The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity) (Probable). Involved in plant defense against insects (By similarity). Has very low cytotoxic activity against the human tumor cell lines CEM and Molt4 (PubMed:10785398). Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA. Strongly inhibited by asialofetuin and asialomucin. Tetramer of four pairs of disulfide bound A-B chains. Expressed in rhizome and more abundantly in leaves (at protein level). The B-chain consists of six tandemly repeated subdomains. Only subdomains 1-alpha and 2-gamma possess a functional carbohydrate-binding site. The precursor is processed in two chains, A and B, that are linked by a disulfide bond. Glycosylated. Belongs to the ribosome-inactivating protein family. Type 2 RIP subfamily.