Toxic But Exploitable Actions Of Ribosome-Inactivating Proteins

Ribosome-inactivating proteins are produced by a wide range of organisms including bacteria, fungi, and plants. The vast majority of ribosome-inactivating proteins have been reported from plants. There are two major types. Type 1 ribosome-inactivating proteins are single-chain proteins with a molecular weight in the vicinity of 30 kDa. Type 2 ribosome-inactivating proteins with a molecular weight close to 60 kDa are composed of a ribosome-inactivating protein chain and a lectin chain. Ribosome-inactivating proteins are characterized by RNA N-glycosidase activity and the ability to inhibit translation in a cell-free rabbit reticulocyte lysate system. Their toxic actions, including antiviral, antibacterial, antifungal, antiparasite, entomotoxic, embryotoxic, and anticancer activities, are reviewed in this chapter.