H-Asn-Asp-Asp-Cys-Glu-Leu-Cys-Val-Asn-Val-Ala-Cys-Thr-Gly-Cys-Leu-OH Trifluoroacetate (Disulfide bonds between Cys⁴ and Cys¹²/Cys⁷ and Cys¹⁵)