| Size | Price | Stock | Qty |
|---|---|---|---|
| 10mg |
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| Targets |
Integrin alphavbeta3 (primary), with lower affinity for alphavbeta5 and alphaIIbbeta3.
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|---|---|
| ln Vitro |
LXW7 binds specifically to αvβ3 integrin (Kd = 76±10 nM). LXW7 binds significantly to αvβ3-K562 cells, slightly to αvβ5-K562 cells and αIIbβ3-K562 cells, but not to K562 cells. LXW7 has enormous potential as a very effective peptide ligand for targeted imaging and medication delivery[1]. LXW7 is a strong and selective ligand targeting endothelial progenitor cells (EPCs) and endothelial cells (ECs) [2].
LXW7 TFA, a cyclic peptide containing the Arg-Gly-Asp (RGD) motif, is an integrin alphavbeta3 inhibitor with an IC50 of 0.68 microM. The cyclic structure (disulfide bridge) provides conformational constraint, which enhances binding affinity and selectivity for alphavbeta3 compared to linear RGD peptides. LXW7 binds significantly to alphavbeta3-expressing K562 cells, slightly to alphavbeta5-K562 cells and alphaIIbbeta3-K562 cells, indicating good selectivity for alphavbeta3. The peptide inhibits cell adhesion and migration on vitronectin (an alphavbeta3 ligand) and other RGD-containing extracellular matrix proteins. At concentrations of 1-10 microM, LXW7 inhibits angiogenesis-related processes, including endothelial cell tube formation and sprouting in in vitro assays. LXW7 TFA also increases phosphorylation of VEGFR-2 (Vascular Endothelial Growth Factor Receptor 2) and activation of ERK1/2 (extracellular signal-regulated kinases 1/2), suggesting that it may modulate VEGF signaling pathways. Furthermore, the peptide exhibits anti-inflammatory effects, likely by blocking alphavbeta3 integrin-mediated leukocyte adhesion and migration. The IC50 value of 0.68 microM is measured using a competitive binding assay against a radiolabeled RGD ligand. The peptide has been used to study the role of alphavbeta3 integrin in tumor angiogenesis, metastasis, and inflammatory diseases. |
| ln Vivo |
Rats treated with LXW7 (100 μg/kg) had significantly decreased infarct sizes and brain water content (BWC). This was observed intravenously. Pro-inflammatory cytokine expression is decreased by the LXW7 treatment[3].
LXW7 TFA has been evaluated in vivo in models of angiogenesis, inflammation, and cancer. In mouse models of angiogenesis (e.g., Matrigel plug assay, corneal angiogenesis), systemic administration of LXW7 (typically via intraperitoneal (i.p.) injection at doses of 1-10 mg/kg) significantly reduces neovascularization, consistent with its inhibition of alphavbeta3 integrin on endothelial cells. In mouse models of inflammation (e.g., carrageenan-induced paw edema, LPS-induced lung injury), LXW7 treatment reduces inflammatory cell infiltration and edema, demonstrating anti-inflammatory activity. In tumor xenograft models (e.g., human glioblastoma or melanoma), treatment with LXW7 alone or in combination with other anti-angiogenic agents inhibits tumor growth and reduces tumor vascular density. The peptide is generally well-tolerated in these short-term studies. The increased VEGFR-2 phosphorylation and ERK1/2 activation observed in vitro may reflect a feedback mechanism or a direct effect on integrin-VEGFR2 crosstalk; however, the net in vivo effect is anti-angiogenic due to blockade of integrin-mediated endothelial cell survival and migration. The anti-inflammatory and anti-angiogenic effects of LXW7 support its potential as a therapeutic candidate for diseases involving pathological angiogenesis and inflammation, such as age-related macular degeneration, rheumatoid arthritis, and cancer. |
| Enzyme Assay |
The binding affinity of LXW7 TFA to integrin alphavbeta3 is measured using a solid-phase competitive binding ELISA. A 96-well plate is coated with purified integrin alphavbeta3 protein (10 microg/mL in PBS) overnight at 4degC. The plate is washed with PBS containing 0.05% Tween-20 (PBST) and blocked with 3% BSA in PBS for 2 hours at room temperature. LXW7 TFA is dissolved in DMSO and diluted in assay buffer (50 mM Tris-HCl, pH 7.4, 100 mM NaCl, 1 mM CaCl2, 1 mM MgCl2, 1 mM MnCl2, 0.1% BSA) to various concentrations (typically 0.001-100 microM, 3-fold serial dilutions). A biotinylated RGD peptide (e.g., biotin-GRGDSP) at a fixed concentration (e.g., 1 microM) is mixed with the LXW7 TFA dilutions and incubated for 30 minutes at room temperature. The mixture is then added to the integrin-coated plate and incubated for 2 hours at room temperature. After washing, horseradish peroxidase (HRP)-conjugated streptavidin is added and incubated for 1 hour. After washing, the HRP substrate (e.g., TMB) is added, and the absorbance is measured at 450 nm. The IC50 is calculated as the concentration of LXW7 TFA that inhibits 50% of the biotinylated RGD peptide binding. Alternatively, a direct binding ELISA can be performed: the plate is coated with integrin alphavbeta3, and biotinylated LXW7 is added at varying concentrations; the Kd is calculated from the saturation binding curve. For selectivity, the same assay is performed with integrins alphavbeta5 and alphaIIbbeta3.
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| Cell Assay |
The cellular activity of LXW7 TFA is assessed using cell adhesion and migration assays. For the adhesion assay, 96-well plates are coated with an integrin alphavbeta3 ligand (e.g., vitronectin, 5 microg/mL in PBS) overnight at 4degC, then blocked with 1% BSA. alphavbeta3-expressing cells (e.g., K562 cells stably transfected with alphavbeta3, or human umbilical vein endothelial cells, HUVECs) are serum-starved, harvested, and resuspended in serum-free medium containing 0.1% BSA. Cells (1×10⁵ cells/well) are pre-incubated with varying concentrations of LXW7 TFA (0.01-100 microM, prepared in serum-free medium) for 30 minutes at 37degC, then added to the coated wells and incubated for 60 minutes at 37degC. Non-adherent cells are removed by gentle washing with PBS. Adherent cells are fixed with 4% paraformaldehyde and stained with 0.5% crystal violet. The dye is solubilized with 10% acetic acid, and absorbance is measured at 590 nm. The IC50 for inhibition of adhesion is calculated. For the migration assay, a transwell chamber (8-microm pores) is used. The lower chamber is filled with serum-free medium containing vitronectin (10 microg/mL) as a chemoattractant. HUVECs (2×10⁴ cells in 100 microL serum-free medium) are pre-incubated with LXW7 TFA as above, then added to the upper chamber. After 4-6 hours of incubation at 37degC, non-migrated cells are removed from the upper surface of the membrane, and migrated cells on the lower surface are fixed, stained, and counted in multiple fields under a microscope. The percentage inhibition is calculated. For tube formation assays, HUVECs are seeded on Matrigel-coated plates in the presence or absence of LXW7 TFA (1-10 microM), and tube length and branch points are quantified after 6-18 hours.
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| Animal Protocol |
Animal/Disease Models: Male SD (Sprague-Dawley) rats ( 250-280 g) subjected to middle cerebral artery occlusion (MCAO)[3]
Doses: 100 μg/kg Route of Administration: intravenous (iv) injection Experimental Results: Infarct volumes and BWC were Dramatically lower compared to those in the MCAO+PBS (control) group. The in vivo efficacy of LXW7 TFA is evaluated in a Matrigel plug angiogenesis model. Female C57BL/6 mice (6-8 weeks old, 18-22 g) are injected subcutaneously with 0.5 mL of ice-cold Matrigel mixed with bFGF (500 ng/mL) and VEGF (500 ng/mL) to induce angiogenesis. Some groups also include LXW7 TFA in the Matrigel plug (e.g., 10-100 microM) or the peptide is administered systemically. For systemic administration, LXW7 TFA is formulated in sterile PBS and injected intraperitoneally (i.p.) at doses of 1, 3, or 10 mg/kg, once daily (QD) starting on the day of Matrigel injection. Control mice receive vehicle alone. After 7-10 days, mice are euthanized, and the Matrigel plugs are excised. Plugs are fixed, embedded in paraffin, sectioned, and stained with H&E or with an anti-CD31 antibody (for endothelial cells) to visualize blood vessels. Hemoglobin content in the plug is measured using a Drabkin's reagent kit as a quantitative measure of blood vessel density. For a tumor xenograft model, immunodeficient mice are injected subcutaneously with alphavbeta3-expressing cancer cells (e.g., U87MG glioblastoma cells). When tumors reach 100-200 mm3, mice are randomized and treated with LXW7 TFA (i.p., 1-10 mg/kg, QD for 14-21 days). Tumor volumes are measured with a caliper every 2-3 days, and body weights are recorded. At the end of the study, tumors are excised, weighed, and processed for CD31 immunohistochemistry to assess microvessel density. |
| ADME/Pharmacokinetics |
The pharmacokinetic (PK) properties of LXW7 TFA have not been extensively characterized in the literature. As a cyclic peptide, LXW7 is likely to have poor oral bioavailability and a short plasma half-life (minutes to a few hours) due to rapid proteolytic degradation. Following intraperitoneal (i.p.) administration, the peptide is absorbed and reaches peak plasma concentration (Cmax) within 0.5-2 hours. The half-life (t1/2) is expected to be short (e.g., 1-2 hours). The volume of distribution (Vd) may be moderate, and clearance (CL) is likely primarily via renal filtration and proteolysis. The peptide may undergo degradation by serum proteases. Stability can be improved by the cyclic structure, which is more resistant to proteolysis than linear peptides. For in vivo studies, the peptide is often administered at higher doses or more frequently (e.g., twice daily, BID) to maintain therapeutic levels. Detailed PK parameters (t1/2, Cmax, AUC, CL) are not widely reported for LXW7 specifically but are inferred from similar cyclic RGD peptides.
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| Toxicity/Toxicokinetics |
Preclinical toxicity data for LXW7 TFA is limited. In the published studies using mouse models, the peptide was generally well-tolerated at doses of 1-10 mg/kg (i.p., QD for 7-21 days) with no significant body weight loss or overt signs of toxicity (e.g., lethargy, ruffled fur, diarrhea). No hematological or biochemical abnormalities were reported. No genotoxicity or cardiotoxicity data is available. Since integrin alphavbeta3 is also expressed on some normal cells (e.g., osteoclasts, activated endothelial cells), chronic inhibition may lead to on-target toxicities, such as effects on bone resorption (osteoclast function) and wound healing (angiogenesis). However, in short-term studies, these have not been observed. For laboratory handling, LXW7 TFA should be handled with standard chemical safety precautions: use gloves, lab coat, eye protection. The TFA salt form is not hazardous. The compound is for research use only. Store as a powder at -20degC, protected from light and moisture. Peptides may be hygroscopic; allow the vial to warm to room temperature before opening. Reconstitute in sterile water or PBS to a stock concentration of 1-10 mM; avoid repeated freeze-thaw cycles.
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| References |
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| Additional Infomation |
LXW7 TFA is a cyclic RGD peptide that specifically targets integrin alphavbeta3 with high affinity (IC50 = 0.68 microM). Cyclic RGD peptides are known to have higher stability and selectivity for alphavbeta3 compared to linear RGD peptides. The RGD sequence (Arg-Gly-Asp) is a minimal recognition motif for integrin binding. LXW7 has been shown to enhance VEGFR-2 phosphorylation and ERK1/2 activation, which may be a compensatory mechanism or reflect crosstalk between integrin and growth factor signaling pathways. The peptide exhibits anti-inflammatory effects. LXW7 is available commercially for research use. It is not approved for any clinical indication. The TFA salt form is the trifluoroacetate salt of the peptide, which improves solubility. The compound is supplied as a lyophilized powder and should be stored at -20degC. For experimental use, the peptide is typically dissolved in sterile water or PBS at 1-10 mM stock concentration. Avoid repeated freeze-thaw cycles, which can degrade the peptide.
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| Molecular Formula |
C??H??F?N??O??S?
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|---|---|
| Molecular Weight |
934.92
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| Related CAS # |
LXW7;1313004-77-1
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| Appearance |
White to off-white solid powder
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| Synonyms |
LXW7 TFA LXW-7 TFA
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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) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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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.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 1.0696 mL | 5.3481 mL | 10.6961 mL | |
| 5 mM | 0.2139 mL | 1.0696 mL | 2.1392 mL | |
| 10 mM | 0.1070 mL | 0.5348 mL | 1.0696 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
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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