Improved factor Xa cleavage of fusion proteins containing maltose binding protein

The addition of five glycine residues at a position adjacent to the factor Xa cleavage site of a MBP-2C fusion protein, comprising maltose binding protein (MBP) and poliovirus 2C, allowed factor Xa to generate both of the component proteins. If, however, MBP-2C was without the above modification, it was cleaved only at a site located internally within poliovirus 2C, and this protein was not, therefore, generated by factor Xa cleavage. A simple procedure is described that uses PCR for the introduction of five glycines adjacent to the factor Xa recognition site.