Properties of the ribosome-inactivating proteins gelonin, Momordica charantia inhibitor, and dianthins

Abstract
The amino acid and sugar compositions of 4 [phytoalexin] ribosome-inactivating proteins (gelonin, M. charantia inhibitor, dianthin 30 and dianthin 32) were determined. The proteins are all basic glycoproteins (pI > 8) containing mannose (more abudnant in gelonin), glucose, xylose, fuxose (absent from gelonin) and glucosamine. The ribosome-inactivating properties of the proteins examined are not modified by pretreatment with N-ethylmaleimide. Precipitating and inactivating antibodies can be raised against ribosome-inactivating proteins; a weak cross-reaction occurred only between dianthin 30 and dianthin 32.