H-Arg-Arg-Trp-Cys-Tyr-Arg-Lys-Cys-Tyr-Lys-Gly-Tyr-Cys-Tyr-Arg-Lys-Cys-Arg-NH2 (Disulfide bonds between Cys⁴ and Cys¹⁷/Cys⁸ and Cys¹³)