rises the amino acid sequence represented by SEQ ID NO:3 (FIG. 3).The precursor protein of the present invention, for example, is a protein in which one or more amino acids, preferably 1 to 10 amino acids, more preferably 1 to 100 amino acids, and still more preferably 1 to 200 amino acids are added to theN-terminal and/or C-terminal amino acid of the above-mentioned protein of the present inventi