TY - JOUR
T1 - Channel-forming activity in the venom of the cockroach-hunting wasp, Ampulex compressa
AU - Gincel, Dan
AU - Haspel, Gal
AU - Libersat, Frederic
N1 - Funding Information:
We are grateful to Varda Shoshan-Barmatz and Noam Zilberberg for their valuable comments on this manuscript and Aviva Weisel-Eichler for the editing. This work was supported by grant 2001044 from the United States–Israel Binational Science Foundation (BSF). We would also like to thank the Kreitman foundation for their support of Gal Haspel and Dan Gincel during their graduate studies.
PY - 2004/5
Y1 - 2004/5
N2 - The parasitoid solitary wasp Ampulex compressa uses the cockroach Periplaneta americana as a food supply for its larvae. To subdue its prey, the wasp injects a venom cocktail into the brain of the cockroach. We investigated channel activity of A. compressa venom by collecting venom and incorporating it into a planar lipid bilayer. The venom, reconstituted into the bilayer, showed ion channel activity, forming a fast-fluctuating channel with a small conductance of 20±0.1pS, with no voltage sensitivity. These channels were not observed when the venom was digested with proteases before application to the bilayer, but were not affected by exposure to protease after their incorporation into the bilayer, indicating that the active venom component is a peptide. The channels were found to be cation selective with similar selectivity for the monovalent cations K+, Li+ and Na+, but showed high selectivity against anions (Cl-) and divalent cations (Ca2+ and Mg2+). This study is the first demonstration and biophysical characterization of channel activity in the venom of A. compressa. The possible functional significance of this channel activity is discussed in light of the unusual nature of the effects of this wasp venom on the behavior of its prey.
AB - The parasitoid solitary wasp Ampulex compressa uses the cockroach Periplaneta americana as a food supply for its larvae. To subdue its prey, the wasp injects a venom cocktail into the brain of the cockroach. We investigated channel activity of A. compressa venom by collecting venom and incorporating it into a planar lipid bilayer. The venom, reconstituted into the bilayer, showed ion channel activity, forming a fast-fluctuating channel with a small conductance of 20±0.1pS, with no voltage sensitivity. These channels were not observed when the venom was digested with proteases before application to the bilayer, but were not affected by exposure to protease after their incorporation into the bilayer, indicating that the active venom component is a peptide. The channels were found to be cation selective with similar selectivity for the monovalent cations K+, Li+ and Na+, but showed high selectivity against anions (Cl-) and divalent cations (Ca2+ and Mg2+). This study is the first demonstration and biophysical characterization of channel activity in the venom of A. compressa. The possible functional significance of this channel activity is discussed in light of the unusual nature of the effects of this wasp venom on the behavior of its prey.
KW - Bioamines
KW - Neurotoxin
KW - Paralysis
KW - Periplaneta americana
KW - Planar lipid bilayer
KW - Pore forming peptide
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U2 - 10.1016/j.toxicon.2004.03.004
DO - 10.1016/j.toxicon.2004.03.004
M3 - Article
C2 - 15109893
AN - SCOPUS:1942501005
SN - 0041-0101
VL - 43
SP - 721
EP - 727
JO - Toxicon
JF - Toxicon
IS - 6
ER -