Peptide Toxins in Solitary Wasp Venoms.
Solitary wasps paralyze insects or spiders with stinging venom and feed the paralyzed preys to their larva. Accordingly, the venoms should contain a variety of constituents acting on nervous systems. However, only a few solitary wasp venoms have been chemically studied despite thousands of species inhabiting the planet. We have surveyed bioactive substances in solitary wasp venoms found in Japan and discovered a variety of novel bioactive peptides. Pompilidotoxins (PMTXs), in the venoms of the pompilid wasps Anoplius samariensis and Batozonellus maculifrons, are small peptides consisting of 13 amino acids without a disulfide bond. PMTXs slowed Na⁺ channel inactivation, in particular against neuronal type Na⁺ channels, and were rather selective to the Nav1.6 channel. Mastoparan-like cytolytic and antimicrobial peptides are the major components of eumenine wasp venoms. They are rich in hydrophobic and basic amino acids, adopting a α-helical secondary structure, and showing mast cell degranulating, antimicrobial and hemolytic activities. The venom of the spider wasp Cyphononyx fulvognathus contained four bradykinin-related peptides. They are hyperalgesic and, dependent on the structure, differently associated with B₁ or B₂ receptors. Further survey led to the isolation of leucomyosuppressin-like FMRFamide peptides from the venoms of the digger wasps Sphex argentatus and Isodontia harmandi. These results of peptide toxins in solitary wasp venoms from our studies are summarized.
Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Toyama, Japan. kkgon@inm.u-toyama.ac.jp.
Katsuhiro
K
Konno
Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Toyama, Japan. cokazuma@inm.u-toyama.ac.jp.
Kohei
K
Kazuma
Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Tochigi, Japan. nihei98@cc.utsunomiya-u.ac.jp.
Ken-ichi
K
Nihei
D000818:Animals; D001920:Bradykinin; D019835:FMRFamide; D006801:Humans; D019476:Insect Proteins / Q000032:analysis / Q000633:toxicity; D010455:Peptides / Q000032:analysis / Q000633:toxicity; D014862:Wasp Venoms / Q000737:chemistry / Q000633:toxicity
D019476:Insect Proteins; D010455:Peptides; D014862:Wasp Venoms; D019835:FMRFamide; D001920:Bradykinin
FMRFamide neuropeptide; bradykinin-related peptide; cytolytic peptide; neurotoxin; peptide toxin; solitary wasp