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Lei Z, Wang H, Zhai Y, Sun M, Chen S, Yin P, Wang X. Insights into the mediation of Ca 2+ signaling in the promoting effects of LETX-VI on the synthesis and release of dopamine. J Cell Commun Signal 2023:10.1007/s12079-023-00783-6. [PMID: 37702818 DOI: 10.1007/s12079-023-00783-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023] Open
Abstract
Latroeggtoxin-VI (LETX-VI) is an active protein and was previously demonstrated to have effects on the synthesis and release of dopamine. Hererin, the involvement of Ca2+ signaling in the effects of LETX-VI on dopamine was systematically investigated, using PC12 cells as a neuron model. LETX-VI was shown to promote dopamine release from PC12 cells both in the presence and absence of extracellular Ca2+; however the presence of extracellular Ca2+ was favorable for enhancing the promoting effects of LETX-VI on dopamine, because LETX-VI facilitated the influx of extracellular Ca2+ through the L-type calcium channels in plasma membrane (PM) to increase cytosolic Ca2+ concentration. LETX-VI was able to penetrate the PM of PC12 cells to act on the Ca2+ channel proteins IP3Rs and RyRs in the endoplasm reticulum (ER) membrane, opening the Ca2+ channels and promoting the release of ER Ca2+ to elevate cytosolic Ca2+ level. With the help of intracellular Ca2+ chelator BAPTA, the elevated cytosolic Ca2+ level was proven to play crucial role for the enhanced promoting effects of LETX-VI on dopamine. Taken together, LETX-VI is able to open the Ca2+ channels in both PM and ER membrane simultaneously to facilitate extracellular Ca2+ influx and ER Ca2+ release, and thus increases the cytosolic Ca2+ concentration to enhance the promoting effects on the synthesis and release of dopamine.
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Affiliation(s)
- Zhixiang Lei
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
| | - Haiyan Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
| | - Yiwen Zhai
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
| | - Minglu Sun
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
| | - Si Chen
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
| | - Panfeng Yin
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China
| | - Xianchun Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China.
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Giglio ML, Boland W, Heras H. Egg toxic compounds in the animal kingdom. A comprehensive review. Nat Prod Rep 2022; 39:1938-1969. [PMID: 35916025 DOI: 10.1039/d2np00029f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: 1951 to 2022Packed with nutrients and unable to escape, eggs are the most vulnerable stage of an animal's life cycle. Consequently, many species have evolved chemical defenses and teamed up their eggs with a vast array of toxic molecules for defense against predators, parasites, or pathogens. However, studies on egg toxins are rather scarce and the available information is scattered. The aim of this review is to provide an overview of animal egg toxins and to analyze the trends and patterns with respect to the chemistry and biosynthesis of these toxins. We analyzed their ecology, distribution, sources, occurrence, structure, function, relative toxicity, and mechanistic aspects and include a brief section on the aposematic coloration of toxic eggs. We propose criteria for a multiparametric classification that accounts for the complexity of analyzing the full set of toxins of animal eggs. Around 100 properly identified egg toxins are found in 188 species, distributed in 5 phyla: cnidarians (2) platyhelminths (2), mollusks (9), arthropods (125), and chordates (50). Their scattered pattern among animals suggests that species have evolved this strategy independently on numerous occasions. Alkaloids are the most abundant and widespread, among the 13 types of egg toxins recognized. Egg toxins are derived directly from the environment or are endogenously synthesized, and most of them are transferred by females inside the eggs. Their toxicity ranges from ρmol kg-1 to mmol kg-1, and for some species, experiments support their role in predation deterrence. There is still a huge gap in information to complete the whole picture of this field and the number of toxic eggs seems largely underestimated.
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Affiliation(s)
- Matías L Giglio
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas, 60 y 120, 1900 La Plata, Argentina.
| | - Wilhelm Boland
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Horacio Heras
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas, 60 y 120, 1900 La Plata, Argentina. .,Cátedra de Química Biológica, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata (UNLP), La Plata, Argentina
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Tang X, Yu D, Wang H, Lei Z, Zhai Y, Sun M, Chen S, Wang Y, Liu Z, Hu W, Wang X. Synaptotagmin 1-mediated cell membrane penetration and dopamine release enhancement by latroeggtoxin-VI. Int J Biol Macromol 2022; 216:906-915. [PMID: 35914553 DOI: 10.1016/j.ijbiomac.2022.07.208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 07/24/2022] [Accepted: 07/25/2022] [Indexed: 11/05/2022]
Abstract
Latroeggtoxin-VI (LETX-VI), a proteinaceous neurotoxin mined from the egg transcriptome of spider L. tredecimguttatus, was previously found to promote the release of dopamine from PC12 cells. However, the relevant molecular mechanism has not been fully clear. Here LETX-VI was demonstrated to rapidly penetrate the plasma membrane of PC12 cells via the vesicle exocytosis/endocytosis cycle, during which vesicular transmembrane protein synaptotagmin 1 (Syt1) functions as a receptor, with its vesicle luminal domain interacting with the C-terminal region of LETX-VI. The C-terminal sequence of LETX-VI is the functional region for both entering cells and promoting dopamine release. After gaining entry into the PC12 cells, LETX-VI down-regulated the phosphorylation levels of Syt1 at T201 and T195, thereby facilitating vesicle fusion with plasma membrane and thus promoting dopamine release. The relevant mechanism analysis indicated that LETX-VI has a protein phosphatase 2A (PP2A) activator activity. The present work has not only probed into the Syt1-mediated action mechanism of LETX-VI, but also revealed the structure-function relationship of the toxin, thus suggesting its potential applications in the drug transmembrane delivery and treatment of the diseases related to dopamine release and PP2A activity deficiency.
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Affiliation(s)
- Xiaochao Tang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Dianmei Yu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Haiyan Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Zhixiang Lei
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Yiwen Zhai
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Minglu Sun
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Si Chen
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Ying Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Zhen Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Weijun Hu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China
| | - Xianchun Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, China.
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Tang X, Yu D, Wang H, Meng W, Lei Z, Zhai Y, Wang Y, Wang X. Biochemical and cytotoxic evaluation of latroeggtoxin-VI against PC12 cells. J Biochem Mol Toxicol 2021; 35:e22825. [PMID: 34047418 DOI: 10.1002/jbt.22825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/27/2021] [Accepted: 05/18/2021] [Indexed: 01/03/2023]
Abstract
Latroeggtoxin-VI (LETX-VI) is a peptide neurotoxin discovered from Latrodectus tredecimguttatus eggs. In the current study, the action features of the neurotoxin on PC12 cells were systematically investigated. LETX-VI could promote dopamine release from PC12 cells in the absence and presence of Ca2+, involving an even more complex action mechanism in the presence of Ca2+ and when the treatment time was longer. Although LETX-VI enchanced the autophagy and secretion activity in PC 12 cells, it showed no remarkable influence on the proliferation, cell cycle, apoptosis and ultrastructure of the cells. Pulldown combined with CapLC-MS/MS analysis suggested that LETX-VI affected PC12 cells by interacting with multiple proteins involved in the metabolism, transport, and release of neurotransmitters, particularly dopamine. The low cytotoxicity and effective regulatory action of LETX-VI on PC12 cells suggest the potential of the active peptide in the development of drugs for the treatment of some dopamine-related psychotic diseases and cancers.
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Affiliation(s)
- Xiaochao Tang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Dianmei Yu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Haiyan Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Wenwen Meng
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Zhixiang Lei
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Yiwen Zhai
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Ying Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Xianchun Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Protein Chemistry Laboratory, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
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Makover V, Ronen Z, Lubin Y, Khalaila I. Eggshell spheres protect brown widow spider ( Latrodectus geometricus) eggs from bacterial infection. J R Soc Interface 2019; 16:20180581. [PMID: 30958158 DOI: 10.1098/rsif.2018.0581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Eggs provide a rich source of nutrients for the developing embryo, making them a favoured food source for other organisms as well. Several defence mechanisms have evolved to protect the developing embryos against microbial threats. In this article, we elucidate the defence strategy of brown widow spider ( Latrodectus geometricus) eggs against bacteria. Antibacterial activity was shown by inhibition of bacterial growth on agar plate, liquid culture and retarded biofilm formation. The defence strategy against bacterial invasion was demonstrated in the whole egg, whole egg extract, egg surface extract, eggshell and eggshell extract. The source and characteristics of this antibacterial activity are distinctive and stem in part from a dense layer of spheres covering the egg surface, likely originated from the oviposition fluid. The spheres are rich in low-molecular-weight proteins, yet their exact composition remains unknown. In this study, we demonstrate that the egg surface is hydrophobic, while the spheres are superhydrophilic. Egg surface roughness and hydrophobicity combined with its antibacterial chemical properties reduce the ability of bacteria to grow on the egg surface. Understanding the properties of these unique structures may contribute significantly to our knowledge of how nature deals with bacterial infections.
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Affiliation(s)
- Vardit Makover
- 1 Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University , Midreshet Ben-Gurion , Israel
| | - Zeev Ronen
- 1 Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University , Midreshet Ben-Gurion , Israel
| | - Yael Lubin
- 2 Marco and Louise Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University , Midreshet Ben-Gurion , Israel
| | - Isam Khalaila
- 3 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University , Beer Sheva , Israel
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Anti-Breast Cancer Activity of Latroeggtoxin-V Mined from the Transcriptome of Spider Latrodectus tredecimguttatus Eggs. Toxins (Basel) 2018; 10:toxins10110451. [PMID: 30400202 PMCID: PMC6266733 DOI: 10.3390/toxins10110451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 10/27/2018] [Accepted: 10/31/2018] [Indexed: 01/08/2023] Open
Abstract
As a black widow spider, Latrodectus tredecimguttatus has poisonous components not only in venomous glands but also in eggs. Our previous work had carried out a transcriptome analysis of the spider eggs in an attempt to probe into the molecular basis of the egg toxicity. A proteinaceous toxin, named Latroeggtoxin-V, was mined from the identified transcriptome. In this study, the gene of Latroeggtoxin-V was cloned and heterologously expressed, and the anticancer activity of the recombinant Latroeggtoxin-V (rLatroeggtoxin-V) was characterized. Activity assay found that rLatroeggtoxin-V could selectively act on breast cancer line MDA-MB-231 cells, not only arresting their cell cycle, inhibiting their proliferation and migration, but also inducing their apoptosis. Bioinformatics analysis suggested that Latroeggtoxin-V belongs to the ATPase inhibitor protein family and the further activity assay showed that the rLatroeggtoxin-V inhibited the activity of the Na+/K+-ATPase in MDA-MB-231 cells in a concentration-dependent manner, suggesting that the anticancer activity of Latroeggtoxin-V is based on its affecting the ion transport and receptor functions of Na+/K+-ATPase. The present work not only laid the foundation for the utilization of Latroeggtoxin-V in the anticancer drug development and the related fields, but also provided a new paradigm for exploration of the proteinaceous toxins under the direction of transcriptomics and bioinformatics.
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Transcriptome Analysis to Understand the Toxicity of Latrodectus tredecimguttatus Eggs. Toxins (Basel) 2016; 8:toxins8120378. [PMID: 27999389 PMCID: PMC5198572 DOI: 10.3390/toxins8120378] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/02/2016] [Accepted: 12/13/2016] [Indexed: 12/21/2022] Open
Abstract
Latrodectus tredecimguttatus is a kind of highly venomous black widow spider, with toxicity coming from not only venomous glands but also other parts of its body as well as newborn spiderlings and eggs. Up to date, although L. tredecimguttatus eggs have been demonstrated to be rich in proteinaceous toxins, there is no systematic investigation on such active components at transcriptome level. In this study, we performed a high-throughput transcriptome sequencing of L. tredecimguttatus eggs with Illumina sequencing technology. As a result, 53,284 protein-coding unigenes were identified, of which 14,185 unigenes produced significant hits in the available databases, including 280 unigenes encoding proteins or peptides homologous to known proteinaceous toxins. GO term and KEGG pathway enrichment analyses of the 280 unigenes showed that 375 GO terms and 18 KEGG pathways were significantly enriched. Functional analysis indicated that these unigene-coded toxins have the bioactivities to degrade tissue proteins, inhibit ion channels, block neuromuscular transmission, provoke anaphylaxis, induce apoptosis and hyperalgesia, etc. No known typical proteinaceous toxins in L. tredecimguttatus venomous glands, such as latrotoxins, were identified, suggesting that the eggs have a different toxicity mechanism from that of the venom. Our present transcriptome analysis not only helps to reveal the gene expression profile and toxicity mechanism of the L. tredecimguttatus eggs, but also provides references for the further related researches.
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Yan S, Wang X. Recent Advances in Research on Widow Spider Venoms and Toxins. Toxins (Basel) 2015; 7:5055-67. [PMID: 26633495 PMCID: PMC4690112 DOI: 10.3390/toxins7124862] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 11/02/2015] [Accepted: 11/16/2015] [Indexed: 01/29/2023] Open
Abstract
Widow spiders have received much attention due to the frequently reported human and animal injures caused by them. Elucidation of the molecular composition and action mechanism of the venoms and toxins has vast implications in the treatment of latrodectism and in the neurobiology and pharmaceutical research. In recent years, the studies of the widow spider venoms and the venom toxins, particularly the α-latrotoxin, have achieved many new advances; however, the mechanism of action of the venom toxins has not been completely clear. The widow spider is different from many other venomous animals in that it has toxic components not only in the venom glands but also in other parts of the adult spider body, newborn spiderlings, and even the eggs. More recently, the molecular basis for the toxicity outside the venom glands has been systematically investigated, with four proteinaceous toxic components being purified and preliminarily characterized, which has expanded our understanding of the widow spider toxins. This review presents a glance at the recent advances in the study on the venoms and toxins from the Latrodectus species.
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Affiliation(s)
- Shuai Yan
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China.
| | - Xianchun Wang
- Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China.
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Isolation and preliminary characterization of proteinaceous toxins with insecticidal and antibacterial activities from black widow spider (L. tredecimguttatus) eggs. Toxins (Basel) 2015; 7:886-99. [PMID: 25785465 PMCID: PMC4379531 DOI: 10.3390/toxins7030886] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 02/12/2015] [Accepted: 03/04/2015] [Indexed: 01/29/2023] Open
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.
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Yan Y, Li J, Zhang Y, Peng X, Guo T, Wang J, Hu W, Duan Z, Wang X. Physiological and biochemical characterization of egg extract of black widow spiders to uncover molecular basis of egg toxicity. Biol Res 2014; 47:17. [PMID: 25027663 PMCID: PMC4101730 DOI: 10.1186/0717-6287-47-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 05/10/2014] [Indexed: 11/16/2022] Open
Abstract
Background Black widow spider (L. tredecimguttatus) has toxic components not only in the venomous glands, but also in other parts of the body and its eggs. It is biologically important to investigate the molecular basis of the egg toxicity. Results In the present work, an aqueous extract was prepared from the eggs of the spider and characterized using multiple physiological and biochemical strategies. Gel electrophoresis and mass spectrometry demonstrated that the eggs are rich in high-molecular-mass proteins and the peptides below 5 kDa. The lyophilized extract of the eggs had a protein content of 34.22% and was shown to have a strong toxicity towards mammals and insects. When applied at a concentration of 0.25 mg/mL, the extract could completely block the neuromuscular transmission in mouse isolated phrenic nerve-hemidiaphragm preparations within 12.0 ± 1.5 min. Using whole-cell patch-clamp technique, the egg extract was demonstrated to be able to inhibit the voltage-activated Na+, K+ and Ca2+ currents in rat DRG neurons. In addition, the extract displayed activities of multiple hydrolases. Finally, the molecular basis of the egg toxicity was discussed. Conclusions The eggs of black widow spiders are rich in proteinous compounds particularly the high-molecular-mass proteins with different types of biological activity The neurotoxic and other active compounds in the eggs are believed to play important roles in the eggs’ toxic actions.
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