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| 1mg |
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| Other Sizes |
| Targets |
Exendin-4, Cy5 labeled specifically targets and binds to the glucagon-like peptide-1 receptor (GLP-1R). GLP-1R is a G-protein coupled receptor expressed on pancreatic beta-cells, as well as in other tissues including the brain, heart, and gastrointestinal tract. Upon binding, the labeled Exendin-4 activates the receptor, leading to increased cAMP production and downstream signaling. The Cy5 fluorescent tag does not interfere with receptor binding, allowing real-time imaging of GLP-1R in vivo.
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| ln Vitro |
In vitro, Exendin-4, Cy5 labeled binds specifically to GLP-1R-expressing cells. It is used to study receptor localization, internalization, and trafficking. The Cy5 tag allows visualization by confocal microscopy or flow cytometry. The compound retains full agonist activity, stimulating cAMP production in cells expressing GLP-1R. It has been shown to bind with high affinity to CHO cells expressing GLP-1R and to primary human islets. It is also used to screen for GLP-1R agonists and antagonists in high-throughput assays.
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| ln Vivo |
In vivo, Exendin-4, Cy5 labeled is used as a beta-cell tracer for imaging GLP-1R expression. It is injected intravenously into animal models, and its distribution is monitored by fluorescence imaging. It specifically accumulates in the pancreas, particularly in the islets of Langerhans, allowing non-invasive visualization of beta-cell mass. This is useful for studying beta-cell dynamics in type 2 diabetes, evaluating islet transplantation, and monitoring the efficacy of diabetes therapies. It has also been used to image GLP-1R-expressing tumors, such as insulinomas and some neuroendocrine tumors.
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| Enzyme Assay |
For receptor binding assays, CHO cells expressing human GLP-1R are seeded in 96-well plates. Exendin-4, Cy5 labeled is added at concentrations of 0.1-100 nM in binding buffer (50 mM HEPES, pH 7.4, 5 mM MgCl2, 0.1% BSA, 0.01% Tween 20). After incubation at 25degC for 1 hour, cells are washed, and fluorescence is measured using a plate reader (Ex/Em: 640/680 nm). Nonspecific binding is determined in the presence of 1 uM unlabeled Exendin-4. For cAMP assays, cells are treated with Exendin-4, Cy5 labeled (0.01-100 nM) for 30 minutes at 37degC, and cAMP levels are measured using a homogeneous time-resolved fluorescence (HTRF) or ELISA kit.
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| Cell Assay |
For cell-based imaging studies, GLP-1R-expressing cells (e.g., INS-1E rat insulinoma cells, primary human islets) are cultured on glass coverslips in appropriate medium (e.g., RPMI-1640 with 10% FBS). Exendin-4, Cy5 labeled is added at 10-100 nM and incubated for 30-60 minutes at 37degC. Cells are washed with PBS and fixed with 4% paraformaldehyde. Coverslips are mounted on slides with DAPI-containing mounting medium and imaged using a confocal microscope (Ex/Em: 640/680 nm). For live-cell imaging, cells are maintained in a temperature-controlled chamber, and images are acquired every 5-10 minutes for 1-2 hours to track receptor internalization. Flow cytometry can also be used to quantify binding.
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| Animal Protocol |
For in vivo imaging studies, mice (e.g., C57BL/6, or diabetic models such as db/db or STZ-induced diabetic mice) are used. Exendin-4, Cy5 labeled TFA is dissolved in sterile PBS (0.1-1 mg/mL) and administered intravenously via the tail vein at a dose of 10-50 ug per mouse (approximately 0.5-2.5 mg/kg). Animals are anesthetized with isoflurane, and images are acquired using an in vivo imaging system (IVIS) or other fluorescence imaging system equipped with Cy5 filters (Ex/Em: 640/680 nm) at various time points (e.g., 0.5, 1, 2, 4, 6, 24 hours post-injection). For ex vivo imaging, animals are euthanized, and organs (pancreas, liver, kidney, lung, heart, brain) are harvested and imaged. For histology, pancreatic tissue is fixed, embedded in paraffin, sectioned, and stained for insulin (immunofluorescence) and Cy5 fluorescence to colocalize Exendin-4 with beta-cells.
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| ADME/Pharmacokinetics |
Exendin-4, Cy5 labeled is a peptide of approximately 4 kDa, which is rapidly cleared by the kidneys if not protected. The terminal half-life (t1/2) in mice is 10-30 minutes, which is similar to unmodified Exendin-4. The compound distributes to the pancreas, kidneys, and liver. It is metabolized by proteases in the blood and tissues, and the Cy5 tag is released and excreted. The rapid clearance limits imaging to short time windows (0.5-6 hours). The compound is not orally bioavailable and is administered intravenously or intraperitoneally for imaging studies.
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| Toxicity/Toxicokinetics |
In animal studies, Exendin-4, Cy5 labeled is well tolerated at imaging doses (0.5-2.5 mg/kg). No acute toxicity is observed. However, the unlabeled Exendin-4 is a potent GLP-1 agonist, and at high doses (>10 mg/kg), it can cause nausea, vomiting, and hypoglycemia in animals. The Cy5 label does not significantly alter the toxicity profile. Prolonged or repeated exposure may lead to the development of anti-Exendin-4 antibodies, which could affect imaging accuracy. Nephrotoxicity due to renal retention of labeled peptides has been reported for radiolabeled Exendin-4, but the fluorescence label is not toxic. For research use, typical doses are safe.
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| References | |
| Additional Infomation |
Exendin-4 is a 39-amino-acid peptide originally isolated from the venom of the Gila monster. It is a potent, long-acting GLP-1 receptor agonist. The FDA-approved drug exenatide (Byetta, Bydureon) is synthetic Exendin-4 used for the treatment of type 2 diabetes. The Cy5-labeled version is a research tool for in vivo imaging of GLP-1R expression, beta-cell mass, and insulinomas. It is not approved for clinical use. It is strictly for research purposes and should be stored at -80degC protected from light to prevent photobleaching. The compound is not recommended for human injection.
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| Molecular Formula |
C225H332CLN55O64S2
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| Molecular Weight |
4931.02
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| Sequence |
His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-{Cys-Mal-CY5}-NH2HGEGTFTSDLSKQMEEEAVRLFIEWLKNGGPSSGAPPPS-{Cys-Mal-CY5}-NH2
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| Appearance |
Typically exists as solids at room temperature
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| Synonyms |
Exendin-4-Cys(Cy5)
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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 |
| 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 | 0.2028 mL | 1.0140 mL | 2.0280 mL | |
| 5 mM | 0.0406 mL | 0.2028 mL | 0.4056 mL | |
| 10 mM | 0.0203 mL | 0.1014 mL | 0.2028 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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