Title
Ampulexins: A New Family of Peptides in Venom of the Emerald Jewel Wasp, Ampulex compressa
Author
Eugene Moore, Ryan Arvidson, Christopher Banks, Jean Urenda, Elizabeth Duong, Haroun Mohammad, Michael E. Adams
Year
2018
Journal
Biochemistry
Abstract
The parasitoid wasp Ampulex compressa injects venom directly into the brain and subesophageal ganglion of the cockroach Periplaneta americana, inducing a seven to ten day lethargy termed hypokinesia. Hypokinesia presents as a significant reduction in both escape response and spontaneous walking. We examined aminergic and peptidergic components of milked venom with HPLC and MALDI-TOF mass spectrometry. HPLC coupled with electrochemical detection confirmed presence of dopamine in milked venom, while mass spectrometry revealed that the venom gland and venom sac have distinct peptide profiles, with milked venom predominantly composed of venom sac peptides. We isolated and characterized novel alpha-helical, amphipathic venom sac peptides that constitute a new family of venom toxins termed ampulexins. Injection of the most abundant venom peptide, ampulexin-1, into the subesophageal ganglion of cockroaches resulted in a short-term increase in escape threshold. Neither milked venom nor venom peptides interfered with growth of Escherichia coli or Bacillus thuringiensis on agar plates and exposure to ampulexins or milked venom did not induce cell death in Chinese hamster ovary cells (CHO-K1) or Hi5 cells (Trichoplusia ni).
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Chemical stability, Biochemistry