Trichosanthin, α-momorcharin and β-momorcharin: identity of abortifacient and ribosome-inactivating proteins

The abortifacient proteins trichosanthin, α-momorcharin and β-momorcharin at nM concentrations inhibit cell-free protein synthesis. The momorcharins and the ribosome-inactivating proteins isolated from Momordica charantia seeds cross-react with the respective antisera. The ribosome-inactivating proteins saporins, pokeweed antiviral protein (PAP) and, to a lesser extent, gelonin have abortifacient activity on pregnant mice.