Vasoconstrictor activity. These toxins cause cardiac arrest probably as a result of coronary vasospasm. Acts by displaying agonistic activities towards endothelin-1 and -2 receptors (EDNRA and EDNRB) (By similarity). Expressed by the venom gland. Different length molecules ranging from 17 (85-101) to 30 amino acids (85-114) have been found in the venom. Monoisotopic mass. Belongs to the endothelin/sarafotoxin family.