Jingzhaotoxin-IX, a novel gating modifier of both sodium and potassium channels from Chinese tarantula Chilobrachys jingzhao

Deng, Mei; Kuang, Fang; Sun, Zhenghua; Tao, Huai; Cai, Tianfu; Zhong, Luanluan; Chen, Zairan; Xiao, Yucheng; Liang, Songping

doi:10.1016/j.neuropharm.2009.04.009

Cited by 22 publications

(18 citation statements)

References 40 publications

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“…The DRGs were acutely isolated from 30-day-old Sprague–Dawley rats of either gender and the neurons prepared from the DRGs were maintained in short-term primary culture according to the methods described previously [38, 39]. The patch-clamp pipettes with a tip resistance of 2.0-3.0 MΩ were made of borosilicate glass capillary tubes.…”

Section: Methodsmentioning

confidence: 99%

Physiological and biochemical characterization of egg extract of black widow spiders to uncover molecular basis of egg toxicity

Yan

Zhang

et al. 2014

biol res

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BackgroundBlack 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.ResultsIn 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.ConclusionsThe 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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Section: Methodsmentioning

confidence: 99%

Physiological and biochemical characterization of egg extract of black widow spiders to uncover molecular basis of egg toxicity

Yan

Zhang

et al. 2014

biol res

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“…Huwentoxin-I is a neurotoxic peptide from venom of the Chinese bird spider Ornithoctonu huwena and has been proven to reduce the peak currents of TTX-S sodium channels in rat DRG neurons, without significant effect on TTX-R sodium currents [20]. Jinzhaotoxins-V and IX (JZTX-V, JZTX-IX) from the venom of Chinese tarantula Chilobrachys jinzhao exhibit inhibitory effects on both TTX-R and TTX-S sodium channels in rat DRG neurons [21,22]. However, to the best of our knowledge, no spider toxins have been reported to selectively inhibit TTX-R sodium channels in rat DRG neurons, without significant effect on TTX-S sodium channels in the same neurons, although a few other animal toxins such as conotoxin mu-SIIA can selectively inhibit TTX-R sodium channels in rat DRG neuron [23].…”

Section: Discussionmentioning

confidence: 99%

“…Whole-cell patch-clamp technique was employed to detect the possible effect of the purified protein on the ion channels in rat dorsal root ganglion (DRG) neurons. DRG neurons were acutely dissected from 30 day old Sprague-Dawley rats of either gender and maintained in short-term primary culture according to the methods described previously [13,14]. Suction pipettes (2.0-3.0 M ) were made of borosilicate glass capillary tubes.…”

Section: Biological and Electrophysiological Assaysmentioning

confidence: 99%

Isolation and identification of a sodium channel-inhibiting protein from eggs of black widow spiders

Jian-jun

Yan

et al. 2014

International Journal of Biological Macromolecules

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“…However, many of these spider venom peptides exhibit a distinct functional profile to the β-scorpion toxins, whereby the peptide traps the DIIS4 voltage sensor in the closed state resulting in an inhibition of peak current [245,255,256]. Although a few of the jingzhaotoxins (Chilobrachys jingzhao) so far discovered have been shown to inhibit Na V current by acting as gating modifiers [244,[257][258][259], only one -β/κ-TRTX-Cj1a (jingzhaotoxin-III) -has so far demonstrated direct binding to the site 4 DIIS3-S4 loop [245]. Two other spider venom peptides that have been shown to bind the DIIS3-S4 linker through mutational analysis include µ-TRTX-Hh2a (huwentoxin-IV isolated from Ornithoctonus huwena) [243] and µ-TRTX-Hhn2a (hainantoxin-III isolated from Ornithoctonus hainana) [255].…”

Section: Site 3 and Sitementioning

confidence: 99%

“…Both of these toxins also inhibit Na V current by interacting with the DIIS3-S4 linker and trapping the voltage sensor in the closed conformation. These Na V inhibitory spider venom peptides acting as gating modulators conform to a similar ICK secondary structure but exhibit highly variable Na V isoform selectivity profiles and promiscuous activity, affecting both Ca V and K V channels [257,259,260]. This promiscuity across members of the voltage-gated ion channel superfamily could be attributed to partial binding in the vicinity of the highly conserved voltage sensor domain (S4) as many of these venom peptides have been shown to bind to S3-S4 linkers of the highly homologous voltage-gated ion channel family [261].…”

Section: Site 3 and Sitementioning

confidence: 99%

Discovery and characterization of NaV modulatory venom peptides

Wingerd¹

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Voltage-gated sodium channels (Na V ) are integral membrane proteins that are responsible for the increase in sodium permeability that initiates and propagates the rising phase of action potentials, carrying electrical signals along nerve fibers and through excitable cells. Na V channels play a diverse role in neurophysiology and neurotransmission, as well as serving as molecular targets for several groups of neurotoxins that bind to different receptor sites and alter voltage-dependent activation, inactivation and conductance. There are nine Na V channel isoforms so far discovered, each of which display distinct functional profiles and tissue-specific expression patterns. The modulation of specific isoforms for therapeutic purposes has become an important research objective for the treatment of conductance diseases exhibiting phenotypes of chronic pain, epilepsy, myotonia, seizure, and cardiac arrhythmia. However, because of the high sequence similarity and structural homology between Na V channel isoforms, many current therapeutics that target Na V channels -the vast majority of which are small molecules -lack specificity between isoforms, or even other voltage-gated ion channels. The current push for greater selectivity while maintaining a relevant degree of potency has led the focus away from small molecules and towards the discovery and development of peptidic ligands for therapeutic use. Venom derived peptides have proven to be naturally potent and selective bioactive molecules, exhibiting inherent secondary structures that add stability through the formation of disulfide bonds. Organisms such as cone snails and spiders have evolved venom for the purpose of prey capture and defense, therefore many of the components exhibit paralytic qualities and specifically target Na V channels. Much of the discovery process has focused on screening crude venoms for a particular function and then isolating the molecule responsible for that function using assay guided purification.The first section of this thesis describes the development of a cell-based, high-throughput functional assay for the detection of Na V modulating venom peptides in crude venom. This assay was successfully implemented and resulted in the isolation and sequencing of MVIA from Conus magus. Initial results and sequence similarity placed MVIA into the δ-conotoxin family, a poorly described class of peptides that inhibits fast inactivation. However, multiple solid-phase synthesis and bacterial recombinant expression methods were unsuccessful in producing enough of the extremely hydrophobic δ-MVIA for further characterization. As no more C. magus crude venom was available, this project was left until optimized methods of production for highly hydrophobic peptides could be developed.ii An optimized method of bacterial recombinant expression was successful in producing large yields of another venom peptide, β/δ-TRTX-Pre1a, isolated from the spider Psalmopoeus reduncus. The same recombinant expression method was also used to produce uniformly label...

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Jingzhaotoxin-IX, a novel gating modifier of both sodium and potassium channels from Chinese tarantula Chilobrachys jingzhao

Cited by 22 publications

References 40 publications

Physiological and biochemical characterization of egg extract of black widow spiders to uncover molecular basis of egg toxicity

Physiological and biochemical characterization of egg extract of black widow spiders to uncover molecular basis of egg toxicity

Isolation and identification of a sodium channel-inhibiting protein from eggs of black widow spiders

Discovery and characterization of NaV modulatory venom peptides

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