Mutant form of a cytotoxic ribonucleolytic protein which allows production by recombinant methods

摘要

The present invention provides recombinant Onc (rOnc) compositions and methods. Recombinant Onc proteins of the invention have an amino terminal methionine and comprise an Onc polypeptide. The amino terminal methionine of the protein allows for recombinant production in a bacterial host cell. Cleaving the amino terminal methionine exposes the amino terminal glutamine of the polypeptide. The Onc polypeptide has an amino terminal glutamine. Cyclization of the amino terminal glutamine of the polypeptide to a pyroglutamyl residue provides rOnc polypeptides and proteins have anti-cancer and anti-viral activity.