Isolation and Preliminary Characterization of Proteinaceous Toxins with Insecticidal and Antibacterial Activities from Black Widow Spider (L. tredecimguttatus) Eggs

Abstract

The eggs of black widow spider (L. tredecimguttatus) have been demonstrated to be rich in toxic proteinaceous components. The study on such active components is of theoretical and practical importance. In the present work, using a combination of multiple biochemical and biological strategies, we isolated and characterized the proteinaceous components from the aqueous extract of the black widow spider eggs. After gel filtration of the egg extract, the resulting main protein and peptide peaks were further fractionated by ion exchange chromatography and reversed-phase high performance liquid chromatography. Two proteinaceous components, named latroeggtoxin-III and latroeggtoxin-IV, respectively, were purified to homogeneity. Latroeggtoxin-III was demonstrated to have a molecular weight of about 36 kDa. Activity analysis indicated that latroeggtoxin-III exhibited neurotoxicity against cockroaches but had no obvious effect on mice, suggesting that it is an insect-specific toxin. Latroeggtoxin-IV, with a molecular weight of 3.6 kDa, was shown to be a broad-spectrum antibacterial peptide, showing inhibitory activity against all five species of bacteria tested, with the highest activity against Staphylococcus aureus. Finally, the implications of the proteinaceous toxins in egg protection and their potential applications were analyzed and discussed.

Dynamics of venom composition across a complex life cycle

“…Chemical protection of the eggs was reported in several animals such as black widow spiders (Buffkin et al, 1971;Lei et al, 2015), snails (Dreon et al, 2013), octopuses and some fishes and amphibians (Bane et al, 2014). Our data on Nematostella NvePTx1 expressed in eggs and embryonic stages further support the idea of ecological importance of chemical defence in early life stages across the animal kingdom.…”

Antimicrobial Activity of Purified Toxins from <i>Crossopriza lyoni</i> (Spider) against Certain Bacteria and Fungi

“…Similar activity was reported in the spider venom peptide Lycosin-II against clinically isolated bacterial pathogens [12] and Latarcins, the versatile spider venom peptides [13]. Spider venom possesses proteinaceous toxins which show remarkable insecticidal and antibacterial activities [14]. Lycosin-I as a shows much higher antipathogenic action in vitro and is used as an alternative antimicrobial drug for treatment of multidrug-resistant Acinetobacter baumannii infections [12] [15], notably, expression of a spider toxin in tobacco inhibits the growth of microbes and insects [16].…”

Transcriptome Analysis to Understand the Toxicity of Latrodectus tredecimguttatus Eggs

“…In our previous studies, latroeggtoxin-I to latroeggtoxin-IV were purified from the eggs and identified to be toxins [16,17,18]. However, they had not been identified to be toxins by BLAST analysis in the present transcriptome of the eggs, because the existing databases had not collected them as toxins when our current work was performed.…”

“…Besides, three high-molecular-mass proteins and one low-molecular-mass peptide, named latroeggtoxin-I to latroeggtoxin-IV, respectively, were purified and characterized from the egg extract. Among them, Latroeggtoxin-I reversibly blocked the neuromuscular transmission in isolated mouse phrenic nerve-hemidiaphragm preparations; latroeggtoxin-II selectively inhibited tetrodotoxin-resistant (TTX-R) sodium channel currents in rat dorsal root ganglion neurons (DRG), without significant effect on the tetrodotoxin-sensitive (TTX-S) sodium channel currents; latroeggtoxin-III showed inhibitory effects on the potassium and calcium channel currents in cockroach dorsal unpaired median (DUM) neurons; and latroeggtoxin-IV was shown to be a broad-spectrum antibacterial peptide [16,17,18]. …”