Purification and characterization of peptides Ap2, Ap3 and Ap5 (ω-toxins) from the venom of the Brazilian tarantula Acanthoscurria paulensis

• Published in: Peptides (New York, N.Y. : 1980) Vol. 145; p. 170622
• Main Authors: Tibery, Diogo Vieira, de Souza, Adolfo Carlos Barros, Mourão, Caroline Barbosa Farias, do Nascimento, Jonathan Martins, Schwartz, Elisabeth Ferroni
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2021
• Subjects: Acanthoscurria; Agatoxins - chemistry; Agatoxins - isolation & purification; Agatoxins - pharmacology; Animals; Calcium Channels, N-Type - metabolism; CHO Cells; Cricetulus; HEK293 Cells; Humans; Ion channel; P/Q-type calcium channel; Peptides - chemistry; Peptides - isolation & purification; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Spider toxin; Spider Venoms - chemistry; Spiders; Voltage-Gated Sodium Channel Blockers - chemistry; Voltage-Gated Sodium Channel Blockers - pharmacology; Voltage-Gated Sodium Channels - genetics; Voltage-Gated Sodium Channels - metabolism; Acanthoscurria; Ion channel; Spider toxin; P/Q-type calcium channel
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2021.170622

•Three novel omega toxins with selectivity for P/Q Channels among tested channels.•Electrophysiological activity of members of a family of Theraphosidae Unknown toxins.•Extensive toxins characterization with purification, mass analysis, sequencing and biological assays on ion channels. Peptides isolated from spider venoms are of pharmacological interest due to their neurotoxic activity, acting on voltage-dependent ion channels present in different types of human body tissues. Three peptide toxins titled as Ap2, Ap3 and Ap5 were purified by RP-HPLC from Acanthoscurria paulensis venom. They were partially sequenced by MALDI In-source Decay method and their sequences were completed and confirmed by transcriptome analysis of the venom gland. The Ap2, Ap3 and Ap5 peptides have, respectively, 42, 41 and 46 amino acid residues, and experimental molecular masses of 4886.3, 4883.7 and 5454.7 Da, with the Ap2 peptide presenting an amidated C-terminus. Amongst the assayed channels – NaV1.1, NaV1.5, NaV1.7, CaV1.2, CaV2.1 and CaV2.2 – Ap2, Ap3 and Ap5 inhibited 20–30 % of CaV2.1 current at 1 μM concentration. Ap3 also inhibited sodium current in NaV1.1, Nav1.5 and Nav1.7 channels by 6.6 ± 1.91 % (p = 0.0276), 4.2 ± 1.09 % (p = 0.0185) and 16.05 ± 2.75 % (p = 0.0282), respectively. Considering that Ap2, Ap3 and Ap5 belong to the 'U'-unknown family of spider toxins, which has few descriptions of biological activity, the present work contributes to the knowledge of these peptides and demonstrates this potential as channel modulators.