| Size | Price | Stock | Qty |
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| 1mg |
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| 5mg |
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| Other Sizes |
| Targets |
Potassium Channel (Kv4 family). Phrixotoxin-1 specifically inhibits A-type potassium currents mediated by Kv4.2 and Kv4.3 channels. It binds to the pore region of these voltage-gated potassium channels and physically occludes the ion conduction pathway, thereby blocking potassium efflux. This interaction alters membrane repolarization and neuronal firing properties. It does not significantly affect other potassium channel subtypes such as Kv1.x, Kv2.1, or Kv7 channels, making it a valuable pharmacological tool for dissecting the contribution of Kv4 channels to native A-type currents in complex cellular systems.
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| ln Vitro |
In vitro, Phrixotoxin-1 has been characterized using patch-clamp electrophysiology in heterologous expression systems and primary neurons. It inhibits Kv4.2 and Kv4.3 currents with high potency, typically in the nanomolar range. In human neural progenitor cells, it has been used to characterize voltage-gated potassium channels, confirming the presence of Kv4-mediated A-type currents. The peptide demonstrates use-dependent block, with its inhibitory efficacy influenced by the gating state of the channel. It does not affect the voltage dependence of activation or inactivation but reduces the overall current amplitude in a concentration-dependent manner.
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| ln Vivo |
In vivo pharmacological data for Phrixotoxin-1 is limited as it is predominantly used as an in vitro research tool. Due to its peptide nature, it has poor blood-brain barrier penetration and is susceptible to proteolytic degradation, limiting its utility in systemic in vivo studies. However, local administration, such as intracerebroventricular or intrathecal injection, could potentially be employed to study Kv4 channel function in specific brain regions. Its spider venom origin suggests that it contributes to the predatory effects of Phrixotrichus auratus, but detailed in vivo pharmacokinetic and pharmacodynamic profiles in mammalian models are not extensively documented in the literature.
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| Enzyme Assay |
In vitro enzyme/receptor binding assays for Phrixotoxin-1 typically involve radioligand binding displacement studies using membrane preparations from cells expressing recombinant Kv4 channels. The peptide is radiolabeled (e.g., with 125I) and incubated with increasing concentrations of unlabeled Phrixotoxin-1 to determine binding affinity (Kd) and competition curves. Alternatively, surface plasmon resonance (SPR) can be used to measure real-time binding kinetics between the peptide and purified Kv4 channel extracellular domains. These assays are performed in physiological buffer solutions at room temperature, with non-specific binding determined in the presence of a large excess of unlabeled peptide or a known Kv4 channel blocker.
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| Cell Assay |
In vitro cell-based assays for Phrixotoxin-1 are primarily performed using patch-clamp electrophysiology in cells heterologously expressing Kv4 channels (e.g., HEK293, CHO cells) or in primary neuronal cultures. Cells are bathed in extracellular recording solution, and whole-cell or outside-out patch configurations are used to record potassium currents. Phrixotoxin-1 is applied via bath perfusion at various concentrations, and the inhibition of peak current amplitude is measured. Toxicity in cultured neurons is assessed using LDH release or MTT assays. Flow cytometry with propidium iodide staining can evaluate cell viability following peptide treatment.
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| Animal Protocol |
In vivo animal experiments with Phrixotoxin-1 are not well-documented in standard research literature. As a research-use peptide toxin, it is primarily utilized in ex vivo or in vitro preparations. If in vivo studies were to be conducted, they would likely involve local microinjection into specific brain regions of rodents to assess effects on neuronal excitability and behavior, followed by histological examination of injection sites. However, no standardized in vivo efficacy or safety animal models have been established for this compound in published literature. Its use remains confined to basic electrophysiological and mechanistic investigations.
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| ADME/Pharmacokinetics |
As a peptide, Phrixotoxin-1 TFA is expected to have poor oral bioavailability and a short plasma half-life due to rapid proteolytic degradation. It is typically administered in vitro directly into aqueous buffers. The TFA salt form enhances its solubility in water and other polar solvents. No systematic ADME (Absorption, Distribution, Metabolism, Excretion) studies have been reported. Its large molecular weight (~3.5 kDa for the peptide portion) and hydrophilic nature limit passive diffusion across cell membranes, necessitating direct application to target tissues in experimental settings.
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| Toxicity/Toxicokinetics |
The toxicological profile of Phrixotoxin-1 has not been systematically characterized in mammalian models. As a spider venom peptide, it is likely to have some inherent toxicity due to its ability to modulate neuronal excitability. At high concentrations, non-specific effects on other ion channels or membrane integrity could occur. No LD50 values or repeated-dose toxicity studies are available. In cell culture, toxicity is typically evaluated alongside functional assays to ensure observed effects are not due to general cytotoxicity. Standard safety pharmacology studies have not been performed for this research compound.
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| References | |
| Additional Infomation |
Phrixotoxin-1 is exclusively a research tool for studying Kv4 potassium channel function, with no clinical development or regulatory approval for therapeutic use. Its mechanism involves specific pore-blocking inhibition of Kv4 channels, which are important for regulating action potential firing in neurons and cardiac rhythmicity. It is commercially available from various biochemical suppliers for laboratory use only. The compound is also known as Phrixotoxin 1 and is referenced in structural biology studies, with its solution structure determined by NMR spectroscopy. It has been cited in studies characterizing potassium channels in human neural progenitor cells.
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| Molecular Formula |
C156H240N44O37S7.XC2HF3O2
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| Molecular Weight |
3548.30 (free base)
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| Appearance |
White to off-white solid powder
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
H2O :≥ 100 mg/mL
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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