Abstract
The venom of the spider Heteropoda venatoria produced lethal effect to cockroaches as reported in our previous study, and could be a resource for naturally-occurring insecticides. The present study characterized a novel cockroach voltage-gated sodium channels (NaVs) antagonist, μ-sparatoxin-Hv2 (μ-SPRTX-Hv2 for short), from this venom. μ-SPRTX-Hv2 is composed of 37 amino acids and contains six conserved cysteines. We synthesized the toxin by using the chemical synthesis method. The toxin was lethal to cockroaches when intraperitoneally injected, with a LD50 value of 2.8 nmol/g of body weight. Electrophysiological data showed that the toxin potently blocked NaVs in cockroach dorsal unpaired median (DUM) neurons, with an IC50 of 833.7 ± 132.2 nM, but it hardly affected the DUM voltage-gated potassium channels (KVs) and the DUM high-voltage-activated calcium channels (HVA CaVs). The toxin also did not affect NaVs, HVA CaVs, and Kvs in rat dorsal root ganglion (DRG) neurons, as well as NaV subtypes NaV1.3–1.5, NaV1.7, and NaV1.8. No envenomation symptoms were observed when μ-SPRTX-Hv2 was intraperitoneally injected into mouse at the dose of 7.0 μg/g. In summary, μ-SPRTX-Hv2 is a novel insecticidal toxin from H. venatoria venom. It might exhibit its effect by blocking the insect NaVs and is a candidate for developing bioinsecticide.
Highlights
Spiders are the most abundant and successful terrestrial predators, and their venoms are cocktails of toxins including cysteine-rich peptides, neurotoxic proteins, histolytic enzymes, digestive enzymes, linear cytolytic peptides, acylpolyamines, small acids, and amines [1]
The venom of the spider H. venatoria was purified by RP-HPLC (Figure 1A), the eluted fractions were lyophilized and their activities to novel cockroach voltage-gated sodium channels (NaVs) s in acutely dissociated cockroach dorsal unpaired median (DUM) neurons were tested
This toxin was described as a secretory peptide in the cDNA library database, and we rationally named the toxin ‘μ-sparatoxin-Hv2’ (‘μ-SPRTX-Hv2’, for short) following the nomenclature rules suggested by King, G
Summary
Spiders are the most abundant and successful terrestrial predators, and their venoms are cocktails of toxins including cysteine-rich peptides, neurotoxic proteins, histolytic enzymes, digestive enzymes, linear cytolytic peptides, acylpolyamines, small acids, and amines [1]. Cysteine-rich peptide toxins are rich components of most spider venoms. There are over 47,000 recorded spider species (World Spider Catalog, version 19.0), with some spider venoms containing >1000 different peptides [2]. There is a great diversity for spider peptide toxins. Many of these toxins had been proven to be insecticidal and some of them are promising bioinsecticide candidates.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
