PhcrTx2, a new crab-paralyzing peptide toxin from the sea anemone Phymanthus crucifer
Rodríguez, A.A.; Garateix, A.; Salceda, E.; Peigneur, S.; Zaharenko, A.J.; Pons, T.; Santos, Y.; Arreguin, R.; Ständker, L.; Forssmann, W.-G.; Tytgat, J.; Vega, R.; Soto, E. (2018). PhcrTx2, a new crab-paralyzing peptide toxin from the sea anemone Phymanthus crucifer. Toxins 10(2): 72. https://dx.doi.org/10.3390/toxins10020072 In: Toxins. Multidisciplinary Digital Publishing Institute (MDPI): Basel. e-ISSN 2072-6651, more |   |
| Keywords | Phymanthus crucifer (Le Sueur, 1817) [WoRMS]
Marine/Coastal | | Author keywords | sea anemone; neutoxin; glutamate receptor; defensin-like fold; ionchannels; Phymanthus crucifer |
| Authors | | Top | - Rodríguez, A.A.
- Garateix, A.
- Salceda, E.
- Peigneur, S., more
- Zaharenko, A.J.
| - Pons, T.
- Santos, Y.
- Arreguin, R.
- Ständker, L.
| - Forssmann, W.-G.
- Tytgat, J., more
- Vega, R.
- Soto, E.
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| Abstract | Sea anemones produce proteinaceous toxins for predation and defense, including peptide toxins that act on a large variety of ion channels of pharmacological and biomedical interest. Phymanthus crucifer is commonly found in the Caribbean Sea; however, the chemical structure and biological activity of its toxins remain unknown, with the exception of PhcrTx1, an acid-sensing ion channel (ASIC) inhibitor. Therefore, in the present work, we focused on the isolation and characterization of new P. crucifer toxins by chromatographic fractionation, followed by a toxicity screening on crabs, an evaluation of ion channels, and sequence analysis. Five groups of toxic chromatographic fractions were found, and a new paralyzing toxin was purified and named PhcrTx2. The toxin inhibited glutamate-gated currents in snail neurons (maximum inhibition of 35%, IC50 4.7 µM), and displayed little or no influence on voltage-sensitive sodium/potassium channels in snail and rat dorsal root ganglion (DRG) neurons, nor on a variety of cloned voltage-gated ion channels. The toxin sequence was fully elucidated by Edman degradation. PhcrTx2 is a new β-defensin-fold peptide that shares a sequence similarity to type 3 potassium channels toxins. However, its low activity on the evaluated ion channels suggests that its molecular target remains unknown. PhcrTx2 is the first known paralyzing toxin in the family Phymanthidae. |
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