Gelonin

Gelonin is known as the "ribosome-inactivating protein" and is currently on the radar of a lot of researchers, as a potential treatment for cancer. Gelonin is a protein toxin of approximately 30 kDa found in the seeds of the Himalayan plant Gelonium multiflorum. In cell-free systems gelonin exerts powerful N-glycosidase activity on the 28S rRNA unit of eukaryotic ribosomes by cleaving out adenine at the 4324 site. Gelonin lacks carbohydrate-binding domain, which are comprised as Beta-chains, so it is unable to cross the plasma membrane, making it highly effective in cell free systems.