N-terminal protected peptide having the following sequence: X-Glu-Cys-Lys-Ile-Lys-Gln-Ile-Ile-Asn-Met-Trp-Gln (SEQ ID NO: 1), wherein X is N of the peptide The N-terminal protecting peptide, which is a group for protecting a terminal. [Selection figure] None次の配列:X-Glu-Cys-Lys-Ile-Lys-Gln-Ile-Ile-Asn-Met-Trp-Gln(配列番号1)を有するN末端保護ペプチドであって、Xが上記ペプチドのN末端を保護する基である前記N末端保護ペプチド。【選択図】なし