Mastoparans are a family of tetradecapeptides from wasp venom, that have been shown to directly activate GTP-binding regulatory proteins. These peptides show selectivity among G proteins: they strongly activate Go and Gi but not Gs or Gt. The peptide of this family are composed by 14 amino acids but they can assume different structures.
Jiyao W et al.(2023). "The conserved domain database in 2023.",