Cloning, cDNA sequence analysis and patch clamp studies of a toxin from the venom of the armed spider (Phoneutria nigriventer)

Kalapothakis, Evanguedes; Penaforte, C.L.; Leão, Ricardo M.; Cruz, Jáder Santos; Prado, Vânia F.; Cordeiro, Marta N.; Diniz, Carlos R.; Romano-Silva, Marco Aurélio; Gomez, Marcus V.; Beirão, Paulo Sérgio Lacerda

doi:10.1016/s0041-0101(98)00127-5

Cited by 39 publications

(20 citation statements)

References 32 publications

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“…The disulfide organization is shown at the bottom of the alignment. *Putative activity on ryanodine receptors, based on strong homology with maurocalcine and IpTx A. Scorpion: opicalcines 1 and 2 (this work); cone snails: δ‐TxVIA, µO‐MrVIB, ω‐GVIA, and κ‐PVIIA (24, 25); spiders: Tx3‐2 and Pn3A (46); viruses: McCTL, BsCTL, XcCTL, OpCTL1, and OpCTL2 (32–34). b) Conserved gene structure.…”

Section: Resultsmentioning

confidence: 98%

Evolutionary origin of inhibitor cystine knot peptides

et al. 2003

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The inhibitor cystine knot (ICK) fold is an evolutionarily conserved structural motif shared by a large group of polypeptides with diverse sequences and bioactivities. Although found in different phyla (animal, plant, and fungus), ICK peptides appear to be most prominent in venoms of cone snail and spider. Recently, two scorpion toxins activating a calcium release channel have been found to adopt an ICK fold. We have isolated and identified both cDNA and genomic clones for this family of ICK peptides from the scorpion Opistophthalmus carinatus. The gene characterized by three well-delineated exons respectively coding for three structural and functional domains in the toxin precursors illustrates the correlation between exon and module as suggested by the "exon theory of genes." Based on the analysis of precursor organization and gene structure combined with the 3-D fold and functional data, our results highlight a common evolutionary origin for ICK peptides from animals. In contrast, ICK peptides from plant and fungus might be independently evolved from another ancestor.

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Section: Resultsmentioning

confidence: 98%

Evolutionary origin of inhibitor cystine knot peptides

et al. 2003

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“…The poison is composed of three neurotoxins and lethal fractions for mice, called PhTx1, PhTx2 and PhTx3 [10] and a different fraction, PhTx4, that modifies the neuromuscular response in insects [11,12]. From these fractions some pure neurotoxins have been characterized, identified [10,11,13–15] and cloned [16]. The PhTx2 fraction is composed of nine different peptides, which are mostly responsible for the effect of the total poison.…”

Section: Discussionmentioning

confidence: 99%

Penile erection induced in vivo by a purified toxin from the Brazilian spider Phoneutria nigriventer

et al. 2008

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smooth muscle, thus causing penile erection. Thirty-five mice were divided in two groups; 10 control mice were injected 20 µ L of saline solution, and in the treated group, 25 mice were divided into groups of five and each subgroup received eretina in decreasing doses (0.024, 0.012, 0.006, 0.003 and 0.0015 µ g/kg) until the minimum dose that produced an erection was determined. After treatment all mice were monitored to determine the response and any collateral effects. RESULTSThe minimum dose producing an erection was 0.006 µ g/kg, the five mice in this group having evidence of an erection at 35-45 min after injection. The histology of the cavernosum of mice treated with eretina showed dilatation and congestion of the vascular spaces with more blood than in controls. With the minimum dose there were no local or systemic collateral effects and the erection was lost after 120-140 min. CONCLUSIONThe minimum dose of eretina producing an erection in mice was determined, and the agent was safe for this use as it did not produce any collateral toxic effects. These studies indicate a possible means of determining the mechanism of action of eretina.

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“…Recently, several homologs of mu-agatoxin were identified in Australian funnel-web spiders (Atrax robustus) [40]. The same scaffold is also widely adopted by other spider toxins, such as w-Aga-IV (Agelenopsis aperta) [41], PNTx3 -2, PRTx22C5 (Phoneutria nigriventer) [42], LiTx2 (Loxosceles intermedia) [43], d-paluIT4 (Paracoelotes luctuosus) [44] and the toxin AcTx (Hadronyche infensa) [45]. JZTX-54 and JZTX-55 may be the first mu-agatoxin-like peptides reported from the venom of tarantula spider.…”

Section: Classification Of the Cktsmentioning

confidence: 99%

Molecular diversity and evolution of cystine knot toxins of the tarantula Chilobrachys jingzhao

Chen

Deng

et al. 2008

Cell. Mol. Life Sci.

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Cystine knot toxins (CKTs) in spider venoms represent a rich source of novel ligands for varied ion channels. Here, we identified 95 novel putative CKT precursors by analyzing expressed sequence tags of the tarantula Chilobrachys jingzhao venom gland. Phylogenetics analyses revealed one orphan family and six families with sequence similarity to known toxins. To further investigate the relationships of their structures, functions and evolution, we assayed 10 representative toxins for their effect on ion channels, and performed structure model comparisons, evolution analysis and toxin distribution analysis. This study revealed two major types of CKTs: pore-blocking toxins and gating modifier toxins. A few blockers were observed with relatively high abundance and wide distribution, which may be a category of original toxins that block channels conserved in various preys with relatively high specificity. The gating modifier families contain advanced toxins, usually have many members and interact with diverse regulatory components of channels.

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Cloning, cDNA sequence analysis and patch clamp studies of a toxin from the venom of the armed spider (Phoneutria nigriventer)

Cited by 39 publications

References 32 publications

Evolutionary origin of inhibitor cystine knot peptides

Evolutionary origin of inhibitor cystine knot peptides

Penile erection induced in vivo by a purified toxin from the Brazilian spider Phoneutria nigriventer

Molecular diversity and evolution of cystine knot toxins of the tarantula Chilobrachys jingzhao

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