| abstract |
A process for preparing a B30-threonine-insulin is described which comprises reacting a des-B30-insulin with an excess amount of a threonine derivative represented by the formula wherein Thr is L-threonine residue, R 1 is hydrogen or a hydroxy-protecting group; and R 2 is a carboxyl-protecting group, in the presence of an enzyme specifically acting on the basic-amino-acid carbonyl in peptide linkages. |