One of the distinct characters of Latrodectus tredecimguttatus is that its toxic components exist not only in the venomous glands, but also in the tissues outside the venomous glands and even in the eggs. Investigation on the toxins outside the venomous glands can deepen our understanding of spider toxins and discover new lead molecules with important application prospects. In order to explore the low-abundance proteinaceous toxins in the L. tredecimguttatus eggs, we used bioinformatic strategies to mine a gene sequence encoding a peptide toxin from the transcriptome of L. tredecimguttatus eggs, and then heterologously expressed the gene successfully with a 3'-RACE combined with nest PCR strategy. Biological activity analyses indicated that the expressed peptide toxin, named latroeggtoxin-Ⅵ (LETX-Ⅵ), could inhibit Na⁺ channel currents in ND7/23 cells and promote dopamine release from PC12 cells, without obvious toxicity against Periplaneta americana and bacteria as well as fungi including Staphylococcus aureus and Candida albicans, demonstrating that LETX-Ⅵ is a mammal-specific neurotoxin with a potential application prospect in development of the tool reagents for neurobiological study and the drugs for treating related diseases.
Animals ; Arthropod Proteins/genetics* ; Black Widow Spider/genetics* ; Cloning, Molecular ; Rats ; Spider Venoms/genetics* ; Transcriptome

Latrodectus tredecimguttatus (commonly known as black widow spiders) have toxins not only in their venom glands, but also in other parts of their body, in their eggs and even in the newborn spiderlings. The study on the toxins in venom and materials outside the venom glands of the spiders to elucidate their differences and similarities, evolutional relationship and biological functions is of important theoretical and applicable significance. The development of modern protein chemistry and proteomics techniques has provided efficient means for the study of protein and peptide toxins of L. tredecimguttatus. By using such techniques, the molecular base and action mechanism of the toxins can be revealed at the levels of both single purified proteins and omics. Up to now, although protein chemistry and proteomics study on L. tredecimguttatus toxins have achieved a certain progress, the relevant work particularly that on the toxins in the materials outside the venom glands has to be further deepened.
Animals ; Arthropod Proteins ; chemistry ; Black Widow Spider ; chemistry ; Proteomics ; Venoms ; chemistry