Scorpion toxins are proteins found in the venom of scorpions. Their toxic effect may be mammal- or insect-specific and acts by binding to sodium channels, inhibiting the inactivation of activated channels and blocking neuronal transmission. Scorpion toxins are proteins found in the venom of scorpions. Their toxic effect may be mammal- or insect-specific and acts by binding to sodium channels, inhibiting the inactivation of activated channels and blocking neuronal transmission. The family includes related short- and long-chain scorpion toxins. It also contains a group of proteinase inhibitors from the plants Arabidopsis thaliana and Brassica spp. The Brassica napus (Oil seed rape) and Sinapis alba (White mustard) inhibitors, inhibit the catalytic activity of bovine beta-trypsin and bovine alpha-chymotrypsin, which belong to MEROPS peptidase family S1 (InterPro: IPR001254).