Method for producing an active protein

Abstract

An active protein can be easily, safely produced by a method comprising providing a first peptide fragment having a first amino acid sequence corresponding to part of an active protein and a second peptide fragment having a second amino acid sequence corresponding to the remaining part of the active protein, at least one of said first peptide fragment and said second peptide fragment being one which has been obtained by recombinant DNA technique or has been obtained by a method comprising producing a predetermined peptide fragment by recombinant DNA technique and deleting from or adding to said predetermined peptide fragment at its N-terminus at least one amino acid residue; and linking said first peptide fragment at its C-terminus to said second peptide fragment at its N-terminus. The method of the present invention may be practiced, with further advantages, by predeterming said first peptide fragment and said second peptide fragment so that a first occurring methionine residue subsequent to the N-terminal amino acid residue of the active protein constitutes the N-terminal amino acid of the amino acid sequence of said second peptide fragment, or so that an amino acid residue positioned near the first occurring methionine residue subsequent to the N-terminal amino acid residue of the desired protein on the side of the N-terminus of the desired protein constitutes the N-terminal amino acid residue of said second peptide fragment.