A Novel Insecticidal Spider Peptide that Affects the Mammalian Voltage-Gated Ion Channel hKv1.5.

Diana Alvarado,Pavel Andrei Montero-Dominguez,Ferenc Papp,Agota Csoti,Fernando Zamudio,Ligia-Luz Corrales-García,Gerardo Corzo,Samuel Cardoso-Arenas,Jesús Borrego,Timoteo Olamendi-Portugal,Herlinda Clement,Gyorgy Panyi,Iván Arenas

doi:10.3389/fphar.2020.563858

Diana Alvarado, Pavel Andrei Montero-Dominguez + Show 11 more

Open Access

https://doi.org/10.3389/fphar.2020.563858

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Abstract

Spider venoms include various peptide toxins that modify the ion currents, mainly of excitable insect cells. Consequently, scientific research on spider venoms has revealed a broad range of peptide toxins with different pharmacological properties, even for mammal species. In this work, thirty animal venoms were screened against hKv1.5, a potential target for atrial fibrillation therapy. The whole venom of the spider Oculicosa supermirabilis, which is also insecticidal to house crickets, caused voltage-gated potassium ion channel modulation in hKv1.5. Therefore, a peptide from the spider O. supermirabilis venom, named Osu1, was identified through HPLC reverse-phase fractionation. Osu1 displayed similar biological properties as the whole venom; so, the primary sequence of Osu1 was elucidated by both of N-terminal degradation and endoproteolytic cleavage. Based on its primary structure, a gene that codifies for Osu1 was constructed de novo from protein to DNA by reverse translation. A recombinant Osu1 was expressed using a pQE30 vector inside the E. coli SHuffle expression system. recombinant Osu1 had voltage-gated potassium ion channel modulation of human hKv1.5, and it was also as insecticidal as the native toxin. Due to its novel primary structure, and hypothesized disulfide pairing motif, Osu1 may represent a new family of spider toxins.

Highlights

Spider venoms are a heterogeneous mixture of molecules that range from enzymes to toxic peptides and small organic components (Pineda et al, 2014)
We look for spider peptides that target the voltage-gated potassium channels (Kv), the hKv1.5 potassium channel, in which ion currents are referred to IKur, and they are the main ion currents in the repolarization of the atrial action potential (AP)
Here we report the primary structure of a spider toxin, named Osu1, that affects hKv1.5, and it seems to be one of the first electric-current modifier peptides of this ion channel

Summary

Introduction

Spider venoms are a heterogeneous mixture of molecules that range from enzymes to toxic peptides and small organic components (Pineda et al, 2014). There are disulfiderich neurotoxins harmful to insects, and perhaps due to molecular serendipity, some of them are toxic to mammals, which affect cell receptors, especially ion channels. Most of the spider neurotoxins could be considered, from the molecular perspective, as precious and unique molecules to help us to understand some of the ion channels’ mechanisms that are important for physiological purposes (Nicholson and Graudins, 2002). It is well known that spider peptide toxins tend to be promiscuous concerning their selectivity for ion channels. Some could be specific and exclusive to unveil relevant domains of the ion channel structures (Corzo and Escoubas, 2003). The spider δ-atracotoxins (δ-ACTXs), that belong to the NaSpTx spider family 4, are disulfide-rich

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