A novel system for the preparation of orphan receptor ligand peptides

A new system is established for the preparation of biologically active reco mbinant peptides. The system consists of two newly developed chemical metho ds in combination with recombinant DNA technology. One method is a cleavage reaction by cyanylation from a recombinant fusion protein. The other is a scission reaction of an N-terminal extra-methionine by transamination from a recombinant peptide. This system is successfully established for the synt hesis of three orphan receptor ligand peptides; apelin, prolactin-releasing peptide, and galanin-like peptide, isolated in our Research Division. The results show that this system is very versatile and might be useful in the preparation of biologically active peptides.