Method for modifying protein or peptide c-terminal

Abstract

A simple and low-cost method of selectively modifying the C-terminal of a protein or peptide is provided. A method of modifying the C-terminal of a protein or peptide comprises forming an intramolecular oxazolone ring at the C-terminal of the protein or peptide that requires C-terminal modification, and then performing a ring-opening of the oxazolone ring to produce a protein or peptide with a modified C-terminal. Preferred forms include a method in which by reacting the oxazolone ring with a compound containing a nucleophilic group to effect an oxazolone ring-opening, a protein or peptide is produced in which the C-terminal is modified with the compound containing the nucleophilic group, as well as a method in which by reacting the oxazolone ring with an active esterifying agent to effect a ring-opening, the oxazolone is converted to an active ester, which by subsequent reaction with a compound containing a nucleophilic group, produces a protein or peptide in which the C-terminal has been modified with the compound containing the nucleophilic group.