Colombian Scorpion Centruroides margaritatus: Purification and Characterization of a Gamma Potassium Toxin with Full-Block Activity on the hERG1 Channel

Autor: José Beltrán-Vidal, Edson Carcamo-Noriega, Nina Pastor, Fernando Zamudio-Zuñiga, Jimmy Alexander Guerrero-Vargas, Santiago Castaño, Lourival Domingos Possani, Rita Restano-Cassulini
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Toxins, Vol 13, Iss 6, p 407 (2021)
Druh dokumentu: article
ISSN: 2072-6651
34974601
DOI: 10.3390/toxins13060407
Popis: The Colombian scorpion Centruroides margaritatus produces a venom considered of low toxicity. Nevertheless, there are known cases of envenomation resulting in cardiovascular disorders, probably due to venom components that target ion channels. Among them, the humanether-à-go-go-Related gene (hERG1) potassium channels are critical for cardiac action potential repolarization and alteration in its functionality are associated with cardiac disorders. This work describes the purification and electrophysiological characterization of a Centruroides margaritatus venom component acting on hERG1 channels, the CmERG1 toxin. This novel peptide is composed of 42 amino acids with a MW of 4792.88 Da, folded by four disulfide bonds and it is classified as member number 10 of the γ-KTx1 toxin family. CmERG1 inhibits hERG1 currents with an IC50 of 3.4 ± 0.2 nM. Despite its 90.5% identity with toxin ɣ-KTx1.1, isolated from Centruroides noxius, CmERG1 completely blocks hERG1 current, suggesting a more stable plug of the hERG channel, compared to that formed by other ɣ-KTx.
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