Arthropod toxins acting on neuronal potassium channels

Self Cite

Venom glands and soluble venom from the Mexican scorpion Centruroides limpidus (Karsch, 1879) were used for transcriptomic and proteomic analyses, respectively. An RNA-seq was performed by high-throughput sequencing with the Illumina platform. Approximately 80 million reads were obtained and assembled into 198,662 putative transcripts, of which 11,058 were annotated by similarity to sequences from available databases. A total of 192 venom-related sequences were identified, including Na+ and K+ channel-acting toxins, enzymes, host defense peptides, and other venom components. The most diverse transcripts were those potentially coding for ion channel-acting toxins, mainly those active on Na+ channels (NaScTx). Sequences corresponding to β- scorpion toxins active of K+ channels (KScTx) and λ-KScTx are here reported for the first time for a scorpion of the genus Centruroides. Mass fingerprint corroborated that NaScTx are the most abundant components in this venom. Liquid chromatography coupled to mass spectometry (LC-MS/MS) allowed the identification of 46 peptides matching sequences encoded in the transcriptome, confirming their expression in the venom. This study corroborates that, in the venom of toxic buthid scorpions, the more abundant and diverse components are ion channel-acting toxins, mainly NaScTx, while they lack the HDP diversity previously demonstrated for the non-buthid scorpions. The highly abundant and diverse antareases explain the pancreatitis observed after envenomation by this species.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Dissecting Toxicity: The Venom Gland Transcriptome and the Venom Proteome of the Highly Venomous Scorpion Centruroides limpidus (Karsch, 1879)

Cid-Uribe

Meneses

Batista

et al. 2019

Self Cite

“…The scorpion toxins that affect K + ion channels (KScTx) are, essentially, blockers of these channels. They are peptides that are 20–75 amino acids long [ 27 ], and have been divided into six subfamilies (α-, β-, γ-, κ-, λ- and ε-KScTx) based on their primary sequence and disulfide bond connectivity, as reviewed in Jiménez-Vargas et al [ 28 ].…”

Section: Resultsmentioning

confidence: 99%

“…The α-KScTx subfamily peptides are characterized by the cysteine-stabilized α/β fold (CSαβ), and are high-affinity blockers of the Kv1 family and the BK K + channels [ 28 ]. We found 16 transcript sequences related to this family ( Supplementary Table S1 ): SgeKTxlAlp01 and SgeKTxAlp08 showing similarity to the precursors named a ‘potassium channel toxin’ (UniProt API81324 and API81322), respectively, from Hemiscorpius lepturus [ 30 ]; SgeKTxAlp02 and SgeKTxAlp06, showing similarity to the precursor named a ‘potassium channel toxin’ (UniProt AHJ59316) from Urodacus.…”

Section: Resultsmentioning

confidence: 99%

Transcriptomic and Proteomic Analyses Reveal the Diversity of Venom Components from the Vaejovid Scorpion Serradigitus gertschi

Romero-Gutiérrez

Santibáñez‐López

Jiménez-Vargas

et al. 2018

To understand the diversity of scorpion venom, RNA from venomous glands from a sawfinger scorpion, Serradigitus gertschi, of the family Vaejovidae, was extracted and used for transcriptomic analysis. A total of 84,835 transcripts were assembled after Illumina sequencing. From those, 119 transcripts were annotated and found to putatively code for peptides or proteins that share sequence similarities with the previously reported venom components of other species. In accordance with sequence similarity, the transcripts were classified as potentially coding for 37 ion channel toxins; 17 host defense peptides; 28 enzymes, including phospholipases, hyaluronidases, metalloproteases, and serine proteases; nine protease inhibitor-like peptides; 10 peptides of the cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 protein superfamily; seven La1-like peptides; and 11 sequences classified as “other venom components”. A mass fingerprint performed by mass spectrometry identified 204 components with molecular masses varying from 444.26 Da to 12,432.80 Da, plus several higher molecular weight proteins whose precise masses were not determined. The LC-MS/MS analysis of a tryptic digestion of the soluble venom resulted in the de novo determination of 16,840 peptide sequences, 24 of which matched sequences predicted from the translated transcriptome. The database presented here increases our general knowledge of the biodiversity of venom components from neglected non-buthid scorpions.

“…Phylogenetically, centipede peptides are divided into 31 families, SCUTX 1-3 and SLPTX 1-28 . Among them, 24 families, including SCUTX 1-2 , SLPTX 1-20 , SLPTX 26 and SLPTX 28 , comprise cysteine-rich peptides with one to eight putative disulfide bonds (Table 1) [1,10,41]. The multiple disulfide bonds confer high chemical, thermal and biological stability on the peptides, enabling researchers to exploit various desirable functions.…”

Section: Centipede Toxins As An Abundant Source Of Drug Leadsmentioning

confidence: 99%

Centipede Venom Peptides Acting on Ion Channels

Chu

Qiu

2020

Centipedes are among the oldest venomous arthropods that use their venom to subdue the prey. The major components of centipede venom are a variety of low-molecular-weight peptide toxins that have evolved to target voltage-gated ion channels to interfere with the central system of prey and produce pain or paralysis for efficient hunting. Peptide toxins usually contain several intramolecular disulfide bonds, which confer chemical, thermal and biological stability. In addition, centipede peptides generally have novel structures and high potency and specificity and therefore hold great promise both as diagnostic tools and in the treatment of human disease. Here, we review the centipede peptide toxins with reported effects on ion channels, including Nav, Kv, Cav and the nonselective cation channel polymodal transient receptor potential vanilloid 1 (TRPV1).