Vasoconstrictor activity. These toxins cause cardiac arrest probably as a result of coronary vasospasm (By similarity). Sarafotoxin-i3: vasoconstrictor activity. Causes cardiac arrest probably as a result of coronary vasospasm (By similarity). Displays low agonistic activities towards endothelin-2 receptor (EDNRB) (displays affinity in the micromolar range). Expressed by the venom gland. Different length molecules ranging from 15 (85-99) to 30 amino acids (85-114) have been found in the venom. RNA editing may explain why no precursor for this sequence have been cloned. Monoisotopic mass, sarafotoxin-i1. Monoisotopic mass, sarafotoxin-i3. Belongs to the endothelin/sarafotoxin family.