Current status of ribosome inactivating proteins

Abstract

Ribosome inactivating proteins (RIPs) are a group of naturally occurring plant proteins with a RNA- N-glycosidases activity which depurinate rRNA at a specific universally conserved position (i.e. cleavage of N-glycosidic bond of a specific adenine of 28S rRNA). These proteins are found in different parts of plants, in concentrations ranging from a few μg to several

hundred mg per 100g of plant tissues. RIPs exist in two forms, type 1 having a single polypeptide chain with a molecular mass of ~ 30 kDa possessing N-glycosidase activity; and type 2 with two or four polypeptide chains having a molecular mass of ~60 kDa and ~120 kDa respectively showing lectin activity along with N-glycosidase moiety. Such biomolecules causing cytotoxicity are being exploited for designing immuilotoxins/hormonotoxins using heterobifunctional conjugates. These carrier conjugates with the RIPs can influence cellular trafficking and inhibition of protein synthesis. We are <span style="font-size:14.0pt;font-family:HiddenHorzOCR;mso-bidi-font-family:HiddenHorzOCR">witnessing &nbsp;a &nbsp;novel protein from plants that can be utilised for various therapeutical treatments ranging from cancers, AIDS and other viral diseases of present times.

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