Site directed mutants of Noxiustoxin reveal specific interactions with potassium channels

Martı́nez, F.; Muñóz-Garay, Carlos; Gurrola, Georgina B.; Darszon, Alberto; Possani, L.D.; Becerril, Baltazar

doi:10.1016/s0014-5793(98)00636-x

Cited by 20 publications

(9 citation statements)

References 24 publications

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“…Characteristic monovalent CatSper currents were recorded in Na + ‐based divalent‐free extracellular solution (Fig H and I; NaDVF) . These monovalent currents are abolished in sperm that lack CatSper . Similar to progesterone, 4‐MBC, DnBP, and TCS reversibly enhanced monovalent currents by about threefold (−60 mV) (Fig H–J, Supplementary Fig S2C and D).…”

Section: Resultsmentioning

confidence: 89%

Direct action of endocrine disrupting chemicals on human sperm

et al. 2014

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Synthetic endocrine disrupting chemicals (EDCs), omnipresent in food, household, and personal care products, have been implicated in adverse trends in human reproduction, including infertility and increasing demand for assisted reproduction. Here, we study the action of 96 ubiquitous EDCs on human sperm. We show that structurally diverse EDCs activate the sperm-specific CatSper channel and, thereby, evoke an intracellular Ca 2+ increase, a motility response, and acrosomal exocytosis. Moreover, EDCs desensitize sperm for physiological CatSper ligands and cooperate in low-dose mixtures to elevate Ca 2+ levels in sperm. We conclude that EDCs interfere with various sperm functions and, thereby, might impair human fertilization.

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Section: Resultsmentioning

confidence: 89%

Direct action of endocrine disrupting chemicals on human sperm

et al. 2014

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“…The primary sequence of many peptide toxins from numerous scorpions are known but few of the structures have been resolved and we know even less of how the particular structure affects the activity [9–11]. Mutating the suspected amino‐acid residues in the toxin sequence has been the method of choice over chemical modification of functional groups of amino acids for understanding the structure–activity relationships [15–18]. However, identification of naturally occurring variants or peptides belonging to the same family with some differences in amino‐acid sequence offers an alternative to mutagenesis for investigating function [19].…”

Section: Discussionmentioning

confidence: 99%

Isolation and characterization of a novel type of neurotoxic peptide from the venom of the South African scorpion Parabuthus transvaalicus (Buthidae)

Inceoglu

Langó

et al. 2001

European Journal of Biochemistry

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The venom of the South African scorpion Parabuthus transvaalicus was characterized using a combination of mass spectrometry and RP-HPLC separation and bioassays. The crude venom was initially separated into 10 fractions. A novel, moderately toxic but very high abundance peptide (birtoxin) of 58 amino-acid residues was isolated, identified and characterized. Each purification step was followed by bioassays and mass spectroscopy. First a C 4 RP-HPLC column was used, then a C 18 RP Microbore column purification resulted in . 95% purity in the case of birtoxin from a starting material of 230 mg of crude venom. About 12-14% of the D 214 absorbance of the total venom as observed after the first chromatography step was composed of birtoxin. This peptide was lethal to mice at low microgram quantities and it induced serious symptoms including tremors, which lasted up to 24 h post injection, at submicrogram amounts. At least seven other fractions that showed different activities including one fraction with specificity against blowfly larvae were identified. Identification of potent components is an important step in designing and obtaining effective antivenom. Antibodies raised against the critical toxic components have the potential to block the toxic effects and reduce the pain associated with the scorpion envenomation. The discovery of birtoxin, a bioactive long chain neurotoxin peptide with only three disulfide bridges, offers new insight into understanding the role of conserved disulfide bridges with respect to scorpion toxin structure and function.

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“…In order to extract the high quality sequence region, ESTs were subjected to the Phred program, with a cutoff Phred score of 20 in a window length of 75 bases [70]. Sequences were processed by removing vector, adaptors and E. coli DNA sequences using CrossMatch [71]. High-quality ESTs were assembled into contigs, using the CAP3 program [72] set to combine only those sequences with at least 98% base identity.…”

Section: Methodsmentioning

confidence: 99%

Profiling the resting venom gland of the scorpion Tityus stigmurus through a transcriptomic survey

et al. 2012

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BackgroundThe scorpion Tityus stigmurus is widely distributed in Northeastern Brazil and known to cause severe human envenoming, inducing pain, hyposthesia, edema, erythema, paresthesia, headaches and vomiting. The present study uses a transcriptomic approach to characterize the gene expression profile from the non-stimulated venom gland of Tityus stigmurus scorpion.ResultsA cDNA library was constructed and 540 clones were sequenced and grouped into 153 clusters, with one or more ESTs (expressed sequence tags). Forty-one percent of ESTs belong to recognized toxin-coding sequences, with transcripts encoding antimicrobial toxins (AMP-like) being the most abundant, followed by alfa KTx- like, beta KTx-like, beta NaTx-like and alfa NaTx-like. Our analysis indicated that 34% of the transcripts encode “other possible venom molecules”, which correspond to anionic peptides, hypothetical secreted peptides, metalloproteinases, cystein-rich peptides and lectins. Fifteen percent of ESTs are similar to cellular transcripts. Sequences without good matches corresponded to 11%.ConclusionsThis investigation provides the first global view of gene expression of the venom gland from Tityus stigmurus under resting conditions. This approach enables characterization of a large number of venom gland component molecules, which belong either to known or non yet described types of venom peptides and proteins from the Buthidae family.

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Site directed mutants of Noxiustoxin reveal specific interactions with potassium channels

Cited by 20 publications

References 24 publications

Direct action of endocrine disrupting chemicals on human sperm

Direct action of endocrine disrupting chemicals on human sperm

Isolation and characterization of a novel type of neurotoxic peptide from the venom of the South African scorpion Parabuthus transvaalicus (Buthidae)

Profiling the resting venom gland of the scorpion Tityus stigmurus through a transcriptomic survey

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