Predicted to enable CD4 receptor binding activity; protein phosphatase binding activity; and sialic acid binding activity. Involved in B cell activation; negative regulation of B cell receptor signaling pathway; and regulation of endocytosis. Located in early endosome and recycling endosome.
Saporin is a so-called ribosome inactivating protein (RIP), due to its N-glycosidase activity, from the seeds of Saponaria officinalis (common name: soapwort).Saporin depurinate the ribosomal RNA in a specific position; rendering the large subunit of ribosomes unable to bind the elongation factors. The consequent arrest of protein synthesis is responsible for the cytotoxicity.