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.
Lu S et al.(2020). "CDD/SPARCLE: the conserved domain database in 2020.",