{"product_id":"phrixotoxin-1-bhp21300271","title":"Phrixotoxin-1","description":"\u003ch2\u003eOverview\u003c\/h2\u003e \u003cp\u003e\u003cstrong\u003ePhrixotoxin-1\u003c\/strong\u003e is a research-grade protein\/peptide reagent used in research settings. It is commonly applied as a tool reagent related to \u003cstrong\u003eKV4.2, KV4.3 channels\u003c\/strong\u003e biology and\/or assay development. It is supplied in Lyophilized format to support flexible downstream use in RUO workflows. Researchers commonly pair it with applications such as Electrophysiology.\u003c\/p\u003e \u003ch2\u003eKey elements and design rationale\u003c\/h2\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eMolecular identity:\u003c\/strong\u003e CAS: 221872-97-5, MW: 3548.4 Da, Formula: C156H240N44O37S7..\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSource \/ origin:\u003c\/strong\u003e Paraphysa scrofa (Chilean copper tarantula) (Phrixotrichus auratus).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality attributes:\u003c\/strong\u003e Purity: ≥99% (HPLC); Bioassay tested: Yes; Sterile \/ endotoxin-free: No.\u003c\/li\u003e \u003c\/ul\u003e \u003ch3\u003eModifications\u003c\/h3\u003e \u003cp\u003eDisulfide bonds between: Cys2-Cys16, Cys9-Cys21, and Cys15-Cys25 Ile29 - C-terminal amidation\u003c\/p\u003e \u003cp\u003eWhen used as a biochemical or pharmacological tool, results are best interpreted relative to the experimental system (species, expression level, and assay readout) and with appropriate negative and competition-style controls where relevant. This product is intended for research use only.\u003c\/p\u003e \u003ch2\u003eBiological background\u003c\/h2\u003e \u003cp\u003ePhrixotoxin-1 (PaTx1) is a 29 amino acid peptidyl toxin isolated from the venom of the theraphosid Phrixotrichus auratus, which potently blocks A-type K+ currents.PaTx1 specifically blocks KV4.3 and KV4.2 currents with a 5 nM \u0026lt; IC50 \u0026lt; 70 nM, by modifying the gating properties of these channels.1As with other spider toxins, PaTx1 presents an active molecular surface, including a hydrophobic patch surrounded by charged residues, which are important for their binding on KV channels. Electrophysiological studies show that the PaTx1 blocks KV4 channels via a mechanism similar to that of hanatoxins on KV2 channels, as they bind and stabilize the preferentially closed state of the channel, in a voltage-dependent manner.2PaTx1 is a crucial tool for understanding the contribution of KV4.3 and KV4.2 in cardiac electrogenesis. Treatment of mice with PaTx1 results in numerous transient cardiac adverse reactions including the occurrence of premature ventricular beats, ventricular tachycardia, different degrees of atrioventricular (AV) blockage and prolongation of the QT interval.1\u003c\/p\u003e \u003ch2\u003eResearch relevance and current trends\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eUsing high-specificity ligands, toxins, and engineered peptides to dissect closely related receptor\/channel subtypes and signaling microdomains.\u003c\/li\u003e\n\u003cli\u003ePairing labeled (e.g., fluorescent) proteins\/peptides with advanced imaging to map surface expression, trafficking, and nanoscale organization.\u003c\/li\u003e\n\u003cli\u003eIncreasing emphasis on reproducibility through standardized characterization (identity, purity, and lot QC) and transparent reporting of reagent attributes.\u003c\/li\u003e \u003c\/ul\u003e \u003ch2\u003eCommon research applications\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eElectrophysiology: commonly used to compare signal, binding, or functional readouts across conditions without implying a specific protocol.\u003c\/li\u003e \u003c\/ul\u003e \u003cp\u003eAcross these use cases, changes in signal or functional readout are generally interpreted as evidence of differences in target abundance, accessibility, or engagement, but alternative explanations (matrix effects, off-target interactions, or assay artifacts) should be considered.\u003c\/p\u003e \u003ch2\u003eNotes for experimental interpretation\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eAssay context matters: binding assays, functional modulation, and detection workflows can yield different readouts even for the same target system.\u003c\/li\u003e\n\u003cli\u003eTarget complexity: closely related family members, splice variants, and post-translational modifications can influence apparent specificity and potency.\u003c\/li\u003e\n\u003cli\u003eMatrix and sample effects: buffer composition, detergents, and biological matrices may alter stability or apparent activity; interpret with appropriate controls.\u003c\/li\u003e\n\u003cli\u003eControl concepts: include negative controls and orthogonal validation (e.g., genetic perturbation or alternative reagents) to support robust interpretation.\u003c\/li\u003e \u003c\/ul\u003e \u003c!-- Sources (internal): - UniProt Knowledgebase (UniProtKB) — UniProt Consortium — https:\/\/www.uniprot.org\/ - NCBI Gene — National Center for Biotechnology Information (NCBI) — https:\/\/www.ncbi.nlm.nih.gov\/gene\/ - NCBI Protein — National Center for Biotechnology Information (NCBI) — https:\/\/www.ncbi.nlm.nih.gov\/protein\/ - PubChem — NIH\/NLM\/NCBI — https:\/\/pubchem.ncbi.nlm.nih.gov\/ - IUPHAR\/BPS Guide to Pharmacology — IUPHAR\/BPS — https:\/\/www.guidetopharmacology.org\/ - RCSB Protein Data Bank (PDB) — RCSB PDB — https:\/\/www.rcsb.org\/ - NCBI Bookshelf — NIH\/NLM — https:\/\/www.ncbi.nlm.nih.gov\/books\/ --\u003e","brand":"Alomone Labs","offers":[{"title":"Default Title","offer_id":53073021403501,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/STP-700_gr_web_465.jpg?v=1772699893","url":"https:\/\/www.ebiohippo.com\/products\/phrixotoxin-1-bhp21300271","provider":"BioHippo","version":"1.0","type":"link"}