Comparative characterization of two scorpion toxins, BlTx1 and BlTx2, identifies BlTx2 as a Kv4.1-selective peptide

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  Comparative characterization of two scorpion toxins, BlTx1 and BlTx2, identifies BlTx2 as a Kv4.1-selective peptide Abstract Voltage-gated potassium channels of the Kv4 subfamily (Kv4.1, Kv4.2, and Kv4.3) mediate transient A-type potassium currents that regulate neuronal excitability, dendritic integration, and cardiac repolarization. Despite their importance, no pharmacological tool has been available to selectively dissect the role of Kv4.1, as existing peptide toxins from the α-KTx15 family display broad activity across Kv4 isoforms. Here, we report the discovery and characterization of two novel scorpion toxins, BlTx1 and BlTx2, isolated from the venom gland transcriptome of  Buthacus leptochelys . Both toxins were heterologously expressed in yeast and purified to homogeneity. Electrophysiological recordings from  Xenopus laevis  oocytes revealed that BlTx1 and BlTx2 potently inhibited Kv4.1 currents, while sparing Kv4.2 and Kv4.3. Among a panel of 20 tested po...

Androctonus ishtar sp. n. from Dohuk and Nineveh provinces, Iraq (Scorpiones: Buthidae)

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Androctonus ishtar sp. n. from Dohuk and Nineveh provinces, Iraq (Scorpiones: Buthidae)

ABSTRACT

A new species, Androctonus ishtar sp. n., is described and illustrated from the Dohuk and Nineveh provinces of Iraq. This new species was previously misidentified as A. crassicauda Olivier. Androctonus sumericus Al-Khazali and Yağmur, and A. turkiyensis Yağmur, are distributed in territories close to those of A. ishtar sp. n. The new species differs from A. crassicauda in the morphology of the fifth metasomal segment, from A. sumericus in its elongate chela, and from A. turkiyensis in the trichobothrial arrangement on the fixed fingers of the chela.

Yağmur, E. A., Kachel, H. S., Al-Khazali, A. M., Al-Jubouri, M. A. K., & Ali, F. R. (2025). Androctonus ishtar sp. n. from Dohuk and Nineveh provinces, Iraq (Scorpiones: Buthidae). Journal of Natural History, 59(25–28), 1757–1773. https://doi.org/10.1080/00222933.2025.2496290