Patent ID: 7335486

Claim:
A method for cleaving a peptide bond of a polypeptide, comprising: combining the polypeptide with clostripain; wherein the polypeptide is any amino acid sequence containing within it at least a fragment having an amino acid sequence of Formula I -Xaa 1 -Xaa 2 -Xaa 3 - (I); wherein Xaa 1 is a residue of aspartic acid, glycine, proline or glutamic acid; Xaa 2 is an arginine residue; Xaa 3 is any amino acid residue other than an acidic amino acid residue; wherein the cleavage is performed between a pH of 6 to 7.0 and at a temperature ranging from 20° C. to 30° C.; wherein the peptide bond cleavage occurs between Xaa 2 and Xaa 3 ; and wherein the cleavage between Xaa 2 and Xaa 3 of Formula I occurs selectively over the cleavage of other arginine or lysine residues within the polypeptide.