This protein markedly relaxes the rat carbachol-precontracted anococcygeus muscle. This relaxation is inhibited by the inhibitor of nitric oxide (NO) synthase, N-nitro-L-arginine methyl ester (L-NAME), suggesting that the response induced by this protein is NO-mediated (By similarity). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.