A process for the mass production of immunoglobulin Fc region residues initial methionine deleted

A production process of an Fc region of free immunoglobulin methionine residue encoded by an initiation codon on a scale mass, comprising: preparing a recombinant expression vector comprising a nucleotide sequence encoding an immunoglobulin Fc region It composed of a recombinant immunoglobulin Fc region linked to an N terminal end thereof to an immunoglobulin hinge region via a peptide bond; transform an E. coli with the recombinant expression vector to create a transformant; culturing the transformant to express the immunoglobulin Fc region as an inclusion body; isolating and purifying the immunoglobulin Fc region of the inclusion body; and solubilize and refold the immunoglobulin Fc fragment, wherein said immunoglobulin hinge region is cysteine, serine or proline as the starting amino acid N-terminal.