Trypsin is a digestive enzyme of serine protease group. It is considered an endopeptidase, i.e., the cleavage occurs within the polypeptide chain rather than at the terminal amino acids located at the ends of polypeptides. Trypsin cleaves peptide chains mainly at the carboxyl side of the amino acids lysine (K) or arginine (R), except when either is followed by proline ( P ) on the C-terminal side or preceded by aspar