Echistatin TFA
Based on 1 Customer Validation
Echistatin TFA is a naturally derived RGD-containing snake venom peptide. Echistatin TFA exhibits an IC50 of 0.6 nM against mouse αvβ3 integrin, and acts as an antagonist against αvβ3, αIIbβ3, α5β1 integrins, pp125FAK and paxillin. Echistatin TFA reduces the phosphorylation of pp125FAK and paxillin, inhibits the autophosphorylation and kinase activity of pp125FAK, and weakens its binding to pp60src and paxillin. Echistatin TFA disrupts the actin cytoskeleton and focal adhesions, induces melanoma cell detachment from fibronectin, and regulates cell adhesion and motility. Echistatin TFA inhibits osteoclast maturation and migration, bone resorption, platelet aggregation, bone loss, as well as adhesion and metastasis of Lewis lung cancer cells; it also increases the number of osteoclasts and bone coverage area in mice with secondary hyperparathyroidism. Echistatin TFA can be used in research related to melanoma, lung cancer and secondary hyperparathyroidism.
For research use only. We do not sell to patients.
- Purity : 99.32%
- Formula: C217H341N71O74S9.xC2HF3O2
- Molecular Weight:5417.00 (free acid)
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Storage:
Sealed storage, away from moisture.
Powder -80°C, 2 years , -20°C, 1 year* In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)
Biological Activity
Description
IC50 & Target
[4]|
αvβ3 |
α5β1 |
αIIbβ3 |
In Vitro
Echistatin (100 μg/mL; 15 min-3 h) TFA reduces the phosphorylation level of pp125FAK Tyr397 in fibronectin-adherent B16-BL6 mouse melanoma cells; decreases the binding level of pp125FAK to paxillin in a time-dependent manner; and inhibits the autophosphorylation of pp125FAK, the phosphorylation of paxillin, and the binding level of pp125FAK to pp60src[1].
Echistatin (100 μg/mL; 30 min) TFA induces detachment of fibronectin-adherent B16-BL6 mouse melanoma cells and causes loss of pp125FAK and paxillin from focal adhesions[1].
Echistatin (10 nCi/tube; 1 h) TFA binds specifically to αvβ3 integrin in membrane fractions enriched from mouse osteoclast-like cells, with an IC50 of 0.6 nM, and this binding is selectively blocked by anti-αvβ3 integrin antibody[2].
Echistatin (100 nM; 7 days, days 0-4, days 4-7) TFA potently inhibits the formation of TRAP-positive multinucleated osteoclast-like cells in a mouse MB1.8 cell-bone marrow co-culture system, with an IC50 of 0.7 nM[2].
Echistatin (10-11 to 10-8 M; 15 h) TFA inhibits M-CSF-induced fusion of mouse mononuclear pre-fusion osteoclasts with an IC50 of 0.6 nM, and inhibits M-CSF-induced migration of mouse mononuclear pre-fusion osteoclasts with an IC50 of 1.0 nM[2].
Echistatin TFA enables the quantitative detection of Echistatin levels in biological samples via competitive receptor binding assays, in which Echistatin extracts from HEK 293 cells overexpressing αvβ3 integrin displace radiolabeled Echistatin[3].
Echistatin (0.1-20 μg/mL; 10 min-6 days) TFA is a reversible, non-cytotoxic inhibitor that suppresses the adhesion of Lewis lung carcinoma (3LL) cells to immobilized fibronectin and laminin in vitro[4].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only. Further protocols information, click here.
In Vivo
Echistatin (6-30 µg/kg/min; subcutaneous injection; continuous infusion; 6 h) TFA inhibits the acute calcemic response to exogenous PTH in parathyroidectomized mice[3].
Echistatin (20 μg; intramuscular injection; co-injected once together with tumor cells) TFA co-administrated with 2.5 × 105 3LL cells via intramuscular injection suppresses tumor growth and metastasis of Lewis lung carcinoma in male C57BL/6NCrlBR mice[4].
Echistatin (1 μg/g; intraperitoneal injection; once every 72 hours; 4 doses total) TFA inhibits Lewis lung cancer tumor growth and metastasis formation in male C57BL/6NCrlBR mice[4].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
Chemical Information
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Appearance Solid
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Molecular Weight 5417.00 (free acid)
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Formula C217H341N71O74S9.xC2HF3O2
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Color White to off-white
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Sequence
Glu-Cys-Glu-Ser-Gly-Pro-Cys-Cys-Arg-Asn-Cys-Lys-Phe-Leu-Lys-Glu-Gly-Thr-Ile-Cys-Lys-Arg-Ala-Arg-Gly-Asp-Asp-Met-Asp-Asp-Tyr-Cys-Asn-Gly-Lys-Thr-Cys-Asp-Cys-Pro-Arg-Asn-Pro-His-Lys-Gly-Pro-Ala-Thr (Disulfide bridge:Cys2-Cys11;Cys7-Cys32;Cys8-Cys37;Cys20-Cys39)
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Sequence Shortening
ECESGPCCRNCKFLKEGTICKRARGDDMDDYCNGKTCDCPRNPHKGPAT (Disulfide bridge:Cys2-Cys11;Cys7-Cys32;Cys8-Cys37;Cys20-Cys39)
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Structure Classification
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Initial Source
snake venoms
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Shipping
Room temperature in continental US; may vary elsewhere.
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Storage
Sealed storage, away from moisture
Powder -80°C 2 years -20°C 1 year * In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)
Solvent & Solubility
In Vitro:
H2O : 50 mg/mL (Need ultrasonic)
In Vivo:
For the following dissolution methods, please prepare the working solution directly:
It is recommended to prepare fresh solutions and use them promptly within a short period of time.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.
Add each solvent one by one: PBS
Solubility: 50 mg/mL; Clear solution; Need ultrasonic
Protocols
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Kinase activity and phosphorylation assays
Kinase activity assays measure the ability of kinases to transfer phosphate groups from ATP to specific substrates, while phosphorylation assays detect the presence and levels of phosphorylated proteins. Common methods include radiolabeled ATP incorporation (e. g. ,), ADP release detection via bioluminescence (e. g. ,[3]), enzyme-linked immunosorbent assays (ELISA) for phospho-specific epitopes (e. g. ,[6]), and microtiter-based formats for high-throughput screening (e. g. ,[8]). The ADP-Glo assay quantifies kinase activity by measuring ADP produced during phosphorylation using a luciferase-based system. Radiometric assays involve autoradiography or scintillation counting after incorporation of 32P-labeled ATP into substrate proteins. ELISA-based approaches rely on phospho-specific antibodies to detect activated kinases in cell lysates or purified samples.
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Western Blot
Western blotting (WB) is a commonly used experimental method in molecular biology, biochemistry, and immunogenetics for identifying and quantifying target proteins. It combines gel electrophoresis with immunoassay, enabling researchers to analyze protein expression, post-translational modifications, and molecular weight.
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Cell Cytotoxicity Assay
Cytotoxicity assays are usually based on the assessment of cell membrane damage, which can also be indirectly detected by measuring cell viability. Detection methods include MTT assay, CKK-8 assay, LDH assay and ATP assay, etc.
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Cell migration
Cell migration is a method that plays an important role in wound healing, cell differentiation, embryonic development, etc.
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Protocol for Kinase activity and phosphorylation assays
Kinase activity assays measure transfer of phosphate from ATP to a protein or peptide substrate, generating phosphorylated substrate, ADP, or incorporated radiolabeled phosphate as the readout; phosphorylation assays measure site-specific phosphorylation in cells or tissues as a proxy for kinase-pathway activation, inhibition, or substrate regulation. Phosphorylation can be detected by phospho-specific Western blot, immunoprecipitation kinase assay, phospho-immunofluorescence, phospho-flow cytometry, luminescent ADP detection, radiolabeled ATP incorporation, or reporter-based pathway assays, and these readouts can be applied to cancer cells, primary neurons, mouse tumors, organoids, inflammatory macrophages, ferroptosis studies, and mitophagy studies when the kinase target is biologically relevant.
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Orthotopic Cell-Line Xenograft
Orthotopic cell-line xenograft models involve implantation of human cancer cell lines into the anatomically corresponding organ of immunodeficient mice to reproduce tumor growth within a native microenvironment, enabling more clinically relevant tumor behavior compared with subcutaneous models. These models are widely used because orthotopic placement better recapitulates tumor progression, including invasion and metastatic spread, which are often underrepresented in heterotopic implantation systems. Compared with conventional xenografts, orthotopic implantation is described as more technically complex but provides improved simulation of tumor-microenvironment interactions and metastatic behavior, making it particularly valuable for translational oncology research. Surgical orthotopic implantation approaches have been emphasized as enabling faithful reproduction of clinical cancer features, including metastasis and disease progression patterns that align with the tumor’s organ of origi
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Phalloidin F-actin cytoskeleton staining
Phalloidin F-actin staining detects polymerized filamentous actin in fixed and permeabilized specimens by using fluorescent phalloidin or phalloidin-derived phallotoxins that bind actin filaments and generate a fluorescence microscopy readout corresponding to F-actin organization, including stress fibers, cortical actin, filament bundles, and tissue-specific actin networks. Phalloidin stabilizes F-actin by reducing actin subunit dissociation from filament ends, and fluorescent phallotoxins were established as tools for visualizing actin-containing structures in eukaryotic cells.
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Osteoclast differentiation from monocyte/macrophage precursors
Osteoclast differentiation is an in vitro induction assay in which monocyte/macrophage-lineage precursors are exposed to macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL), generating multinucleated osteoclasts that are commonly identified by tartrate-resistant acid phosphatase (TRAP) staining and functionally confirmed by resorption pits on dentin, bone, or mineralized substrates. M-CSF supports survival and expansion of osteoclast precursors, while RANKL binding to RANK drives osteoclast commitment, fusion, maturation, and resorptive function; osteoprotegerin inhibits this pathway by binding RANKL and preventing RANK activation. The main readouts are the number of TRAP-positive multinucleated cells, formation of F-actin rings, and resorbed surface area; TRAP-positive multinucleated cells indicate osteoclast differentiation, whereas pit formation on dentin, bone, or mineralized coating indicates functional bone-resorbing activity.
Purity & Documentation
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Data Sheet (336 KB)
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SDS (252 KB)
- English - EN (252 KB)
- Français - FR (252 KB)
- Deutsch - DE (252 KB)
- Norwegian - NO (252 KB)
- Español - ES (252 KB)
- Swedish - SV (252 KB)
- Italian - IT (252 KB)
- Korean - KR (252 KB)
- Portuguese - PT (252 KB)
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Handling Instructions (2659 KB)
References
[1]. Della Morte R, et al. Echistatin inhibits pp125FAK autophosphorylation, paxillin phosphorylation and pp125FAK-paxillin interaction in fibronectin-adherent melanoma cells. European journal of biochemistry. 2000 Aug;267(16):5047-54. [Content Brief]
[2]. Nakamura I, et al. Echistatin inhibits the migration of murine prefusion osteoclasts and the formation of multinucleated osteoclast-like cells. Endocrinology. 1998 Dec;139(12):5182-93. [Content Brief]
[3]. Masarachia P, et al. Histomorphometric evidence for echistatin inhibition of bone resorption in mice with secondary hyperparathyroidism. Endocrinology. 1998 Mar;139(3):1401-10. [Content Brief]
[4]. Spalleticernia D, et al. Echistatin inhibits Lewis lung carcinoma cell-matrix adhesion in vitro and experimental metastasis in vivo. International journal of oncology. 1997 Oct;11(4):757-63. [Content Brief]
Calculators
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)