Ser-Ser-Cys-Tyr-Gly-Gly-Arg-Ile-Asp-Arg-Ile-Gly-Ala-Gln-Ser-Gly-Leu-Gly-Cys-Asn-Ser-Phe-Arg (Disulfide bridge Cys3-Cys19 )C98H156N34O33S2