ribosome-inactivating protein

(Abbreviation: RIP). A class of plant proteins that inhibit normal ribosome function, and are thus highly toxic. Type 1 RIPs consist of single polypeptide chain protein s; type 2 (e.g. ricin) consist of two proteins linked by a disulphide bridge, one the toxin and the other a lectin that attaches to recognition sites on a target cell.