| Size | Price | Stock | Qty |
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| 5mg |
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| 10mg |
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| Other Sizes |
| Targets |
PHF6 (VQIVYK) targets itself-the hexapeptide acts as a nucleation site for tau aggregation. The PHF6 sequence is a critical “prion-like” domain within tau that drives protein misfolding and aggregation. In full-length tau, the PHF6 region adopts a beta-sheet conformation that promotes the formation of tau dimers, oligomers, and ultimately paired helical filaments (PHFs). This hexapeptide is a key contributor to tau‘s propensity to aggregate. By providing a synthetic version of this sequence, PHF6 TFA is used as a minimal model to study tau aggregation in cell-free systems and in cells.
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| ln Vitro |
Aggregated tau-PHF6 (VQIVYK) TFA potentiates NLRP3 inflammasome expression and autophagy in human microglial cells[1].
In vitro, PHF6 (VQIVYK) TFA is a self-assembly hexapeptide that readily aggregates into beta-sheet rich structures. It is used as a minimal model system to study tau aggregation kinetics and to screen for inhibitors of tau aggregation. The peptide can form amyloid-like fibrils under physiological conditions. Its ability to initiate tau aggregation is mapped to the third microtubule-binding repeat region of the full-length tau protein. Aggregation is typically monitored by Thioflavin T fluorescence, circular dichroism, or transmission electron microscopy. No specific IC50 values or detailed cellular activity data are reported for the peptide itself. |
| ln Vivo |
No specific in vivo activity data for PHF6 (VQIVYK) TFA are reported in the search results. The synthetic hexapeptide is not typically administered to animals as a therapeutic or toxic agent. However, it is used as a tool for studying tau aggregation in vitro and in cell culture. In some research contexts, the PHF6 peptide may be used as a seed to induce tau aggregation in tau-expressing cell lines or to study mechanisms of tau spreading. It has been studied in human microglial cells, but no specific in vivo data are provided.
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| Enzyme Assay |
PHF6 is not an enzyme or a receptor; it is an aggregating peptide. Its “binding” is to itself to form higher-order structures. Aggregation kinetics are measured by Thioflavin T (ThT) fluorescence assays. PHF6 peptide is dissolved in hexafluoroisopropanol (HFIP) to monomerize, then dried, and redissolved in DMSO. The peptide is diluted into PBS (pH 7.4) at concentrations of 50-500 microM. Thioflavin T (final 20 microM) is added, and fluorescence is measured at λex=450 nm, λem=485 nm at 37degC over time (0-48 hours). Aggregation is confirmed by transmission electron microscopy (TEM) of negative-stained samples. Fibril morphology is examined. The TFA salt form is used to improve handling and solubility.
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| Cell Assay |
For cellular aggregation assays, tau-expressing cells (e.g., HEK293T cells transfected with full-length tau or tau repeat domain constructs, or tau stably-expressing cell lines such as SH-SY5Y-tau) are seeded in 6- or 96-well plates. The PHF6 peptide (pre-aggregated or monomeric) is added to the culture medium at concentrations of 1-50 microM for 24-72 hours. Alternatively, the peptide can be delivered via lipofection or as pre-formed fibrils (PFFs). Tau aggregation is assessed by Western blot using anti-tau antibodies (e.g., Tau-5, AT8 for phosphorylated tau) or by using the Tau RD P301S FRET biosensor assay (HEK293 cells co-expressing tau repeat domain fused to CFP and YFP). Aggregated tau leads to FRET signal. Immunofluorescence staining for tau (e.g., using MC1 antibody for pathological tau) is performed. PHF6 has also been studied in human microglial cells.
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| Animal Protocol |
No animal experiments for PHF6 (VQIVYK) TFA are described in the search results. For in vivo evaluation of tau aggregation induction, transgenic tauopathy mice (e.g., P301S or rTg4510) or wild-type mice could be injected intracerebrally or intrahippocampally with pre-formed PHF6 aggregates or PFFs. The PHF6 peptide would be pre-aggregated in vitro by incubation at 37degC with shaking for 24-72 hours. Mice (8-12 weeks old) would be stereotaxically injected with 2-5 microL of aggregated PHF6 (50-200 microM) into the hippocampus or entorhinal cortex. At 1-6 months post-injection, brains would be harvested and tau pathology assessed by immunohistochemistry for hyperphosphorylated tau (AT8), Gallyas silver staining for tangles, and Thioflavin S staining for fibrils. No such data are provided in the search results.
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| ADME/Pharmacokinetics |
PHF6 (VQIVYK) TFA is a synthetic hexapeptide with the sequence H-Val-Gln-Ile-Val-Tyr-Lys-OH (TFA salt). The molecular formula is C3₆H₅₈N₈O₉·C2HF3O2 (approximate MW = 790.91 for the free base, plus TFA counterion). The powder is white to off-white. For storage, the lyophilized powder should be kept at -20degC or -80degC, sealed, and protected from moisture and light. For in vitro use, the peptide is dissolved in HFIP or DMSO to make a 1-10 mM stock solution. For aggregation assays, stocks are diluted in PBS (pH 7.4) to the desired concentration (50-500 microM). No PK data are applicable as the peptide is used as an in vitro tool.
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| Toxicity/Toxicokinetics |
The PHF6 hexapeptide is itself an aggregating species and not a drug, but its aggregated forms may be neurotoxic in culture. As a research compound, it is not intended for human or veterinary use. Standard laboratory safety precautions for handling peptides should be followed, including the use of gloves, lab coat, and safety goggles. The TFA counterion may have toxicity at high concentrations but is present in trace amounts in typical assays. No formal toxicology studies are available.
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| References | |
| Additional Infomation |
PHF6 (VQIVYK) is a hexapeptide derived from the third microtubule-binding repeat (R3) of the human tau protein. This sequence was identified as a critical “prion-like” domain responsible for tau aggregation into paired helical filaments (PHFs) and neurofibrillary tangles (NFTs), which are pathological hallmarks of Alzheimer‘s disease and other tauopathies (e.g., frontotemporal dementia, progressive supranuclear palsy, chronic traumatic encephalopathy). PHF6 is widely used as a minimal model system to study the molecular mechanisms of tau aggregation and to screen for small molecule inhibitors of tau aggregation. The PHF6 peptide is also known as the tau PHF6 aggregation core. The TFA (trifluoroacetate) salt form is the industry standard for synthetic peptides, improving solubility and handling. The peptide is for research use only and has no therapeutic applications. It has not received regulatory approval for any indication.
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| Molecular Formula |
C36H60N8O9.XC2HF3O2
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| Molecular Weight |
748.91 (free base)
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| Appearance |
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, avoid exposure to moisture. |
| 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 : ≥ 50 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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