Abstract: The 7 peptide-resin is synthesized by polypeptide synthesizer and Fmoc protected amino acid. The disulfide formation is performed by Tl(Tfa)_3 on the 7 peptide-resin. The side chain protected peptide is cleaved from resin by aminolysis with threoninol. At the same time threoninol is linked to the cleaved peptide. The side chain protective groups is removed by using trifluoroacetic acid(TFA), and the crude linear peptide is purified using HPLC.