{"product_id":"osu1-toxin-bhp21300244","title":"Osu1 Toxin","description":"\u003ch2\u003eOverview\u003c\/h2\u003e \u003cp\u003e\u003cstrong\u003eOsu1 Toxin\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\u003eKv1.5 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 MW: 7477.7 Da, Formula: C332H487N101O83S8.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSource \/ origin:\u003c\/strong\u003e Oculicosa supermirabilis (Central Asian wolf-spider).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality attributes:\u003c\/strong\u003e Purity: ≥ 97% (HPLC); Bioassay tested: Yes; Sterile \/ endotoxin-free: No.\u003c\/li\u003e \u003c\/ul\u003e \u003ch3\u003eModifications\u003c\/h3\u003e \u003cp\u003eDisulfide bonds between: Cys10-Cys26, Cys28-Cys40, Cys17-Cys42, Cys19-Cys56\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\u003eKappa-lycotoxin-Os1a (Osu1 Toxin) is a 64-amino acid peptidyl toxin derived from the venom of the spider Oculicosa supermirabilis1. Osu1 exhibits inhibitory activity at the hKv1.5 channel and slows the activation kinetics of the Kv1.5 current at ~µM peptide concentration. The mode of action of Osu1 toxin involves binding to the voltage-sensing domain of the hKv1.5 potassium channel rather than occluding its pore. This binding effectively prevents the channel's opening at physiological membrane potentials, resulting in the inhibition of the ultra-rapid delayed rectifier potassium current (IKur). Consequently, this prolongs atrial action potentials, potentially leading to the termination of atrial fibrillation (AF)1,2. The hKv1.5 channel is selectively expressed in human atrial myocytes and is absent in ventricular tissues, reducing the likelihood of ventricular side effects. Osu1 toxin demonstrates a high affinity for hKv1.5, and this specificity makes it a promising candidate for selective AF therapies1,2. The potential applications of Osu1 toxin extend beyond AF. Its unique properties make it a valuable tool for studying ion channel physiology and hold promise for the development of toxin-based therapeutics. Osu1's ability to prolong atrial action potentials without affecting ventricular tissues further highlights its therapeutic relevance1,2.\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":53073019371885,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/STK-010_CHO-Kv1.5_178.png?v=1772699890","url":"https:\/\/www.ebiohippo.com\/products\/osu1-toxin-bhp21300244","provider":"BioHippo","version":"1.0","type":"link"}