The rate of protein synthesis inhibition is significantly increased by adding excess ricin B chain to target cells independent of the amount of ricin A chain bound to the cell surface membrane. Ricin is a known toxin from albumin of the castor oil bean and contains an A chain and a B chain for binding...http://www.google.com.au/patents/US4520011?utm_source=gb-gplus-sharePatent US4520011 - Inactivating protein synthesis by incubating anti-Thy 1.1-ricin a chain monoclonal antibody hybrids with target protein cells
