Patent ID: 7981635

Claim:
A method of preparing insulin, an insulin analog or an insulin derivative, comprising the steps of: (a) cleaving a pre-pro-insulin, a pre-pro-insulin analog or a pre-pro-insulin derivative with Ser172Ala porcine trypsin to obtain cleavage products, wherein said Ser172Ala porcine trypsin is activated from the polypeptide as set forth in SEQ ID NO: 3, (b) separating the cleavage products of (a), and (i) if one or more of the cleavage products is an insulin analog or an insulin derivative, performing a further step comprising: obtaining the insulin analog or the insulin derivative, or (ii) if one or more of the cleavage products is a precursor of: insulin, an insulin analog or an insulin derivative, performing further steps comprising: (1) processing the cleavage products to obtain insulin, the insulin analog or the insulin derivative, (2) separating the insulin, the insulin analog or the insulin derivative, and (3) obtaining the insulin, the insulin analog or the insulin derivative wherein the insulin, the insulin analog or the insulin derivative is prepared.