αD-Conotoxins in Species of the Eastern Pacific: The Case of Conus princeps from Mexico
AbstractConus snails produce venoms containing numerous peptides such as the α-conotoxins (α-CTXs), which are well-known nicotinic acetylcholine receptor (nAChR) antagonists. Thirty-eight chromatographic fractions from Conus princeps venom extract were isolated by RP-HPLC. The biological activities of 37 fractions (0.07 µg/µL) were assayed by two-electrode voltage clamp on human α7 nAChRs expressed in Xenopus laevis oocytes. Fractions F7 and F16 notably inhibited the response elicited by acetylcholine by 52.7 ± 15.2% and 59.6 ± 2.5%, respectively. Fraction F7 was purified, and an active peptide (F7-3) was isolated. Using a combination of Edman degradation, mass spectrometry, and RNASeq, we determined the sequence of peptide F7-3: AVKKTCIRSTOGSNWGRCCLTKMCHTLCCARSDCTCVYRSGKGHGCSCTS, with one hydroxyproline (O) and a free C-terminus. The average mass of this peptide, 10,735.54 Da, indicates that it is a homodimer of identical subunits, with 10 disulfide bonds in total. This peptide is clearly similar to αD-CTXs from species of the Indo-Pacific. Therefore, we called it αD-PiXXA. This toxin slowly and reversibly inhibited the ACh-induced response of the hα7 nAChR subtype, with an IC50 of 6.2 μM, and it does not affect the hα3β2 subtype at 6.5 μM. View Full-Text
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Hernández-Sámano, A.C.; Falcón, A.; Zamudio, F.; Batista, C.V.; Michel-Morfín, J.E.; Landa-Jaime, V.; López-Vera, E.; Jeziorski, M.C.; Aguilar, M.B. αD-Conotoxins in Species of the Eastern Pacific: The Case of Conus princeps from Mexico. Toxins 2019, 11, 405.
Hernández-Sámano AC, Falcón A, Zamudio F, Batista CV, Michel-Morfín JE, Landa-Jaime V, López-Vera E, Jeziorski MC, Aguilar MB. αD-Conotoxins in Species of the Eastern Pacific: The Case of Conus princeps from Mexico. Toxins. 2019; 11(7):405.Chicago/Turabian Style
Hernández-Sámano, Arisaí C.; Falcón, Andrés; Zamudio, Fernando; Batista, César V.; Michel-Morfín, Jesús E.; Landa-Jaime, Víctor; López-Vera, Estuardo; Jeziorski, Michael C.; Aguilar, Manuel B. 2019. "αD-Conotoxins in Species of the Eastern Pacific: The Case of Conus princeps from Mexico." Toxins 11, no. 7: 405.
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