[des-Arg1]-Proctolin: A novel NEP-like enzyme inhibitor identified in Tityus serrulatus venom

- We searched for novel small molecules in Tityus serrulatus venom using human NEP as a screening tool.
- We found a NEP-inhibiting peptide with the primary sequence YLPT, named as [des-Arg1]-proctolin.
- NEP inhibition assays showed that [des-Arg1]-proctolin has better inhibitory activity than proctolin.
- We detected NEP-like enzymes in cockroach heads homogenate using thiorphan and [des-Arg1]-proctolin, and also by Western blot analysis.
- [des-Arg1]-proctolin may play a role in human envenomation, as well as in the paralysis and death of insects.