There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Venom from the endoparasitic wasp, Pimpla hypochondriaca, is composed of a mixture
of high and low molecular weight proteins, possesses phenoloxidase activity, has immunosuppressive
properties, and induces paralysis in several insect species. In the present study
we demonstrate that P. hypochondriaca venom also contains antibacterial and proteolytic
activity. Antibacterial activity was detected against the Gram-negative bacteria Escherichia
coli and Xanthamonas campestris but not against Pseudomonas syringae nor against two
Gram-positive bacteria, Bacillus cereus and Bacillus subtilis. Endopeptidase and aminopeptidase
activity in venom was detected using the synthetic fluorogenic substrates N-t-BOC-Phe-Ser-Arg-AMC,
Arg-AMC and Leu-Arg. The aminopeptidase activity towards Arg-AMC was sensitive to
amastatin (70% inhibition), an aminopeptidase inhibitor. Angiotensin-converting enzyme
(ACE)-like enzyme activity was detected, by reverse-phase HPLC using the synthetic
tripeptide Hip-His-Leu as a substrate. This activity was sensitive to captopril, an
ACE inhibitor (IC(50) 3.8 x 10(-8) M). Using an antiserum raised against recombinant
Drosophila melanogaster ACE-like enzyme, (rAnce), Western blot analysis revealed an
immunoreactive protein, with a molecular weight estimate of 74 kDa, in P. hypochondriaca
venom. The possibility that the endopeptidase, aminopeptidase and ACE are involved
in the processing of peptide precursors in the venom sac is discussed.