Recombinant Human VE-Cadherin

Recombinant Human VE-Cadherin (Vascular Endothelial Cadherin) is a valuable tool for a wide range of research applications, particularly in vascular biology, tissue engineering, and studies of endothelial cell function. Here are several compelling reasons to use recombinant human VE-Cadherin in your research:

1. Promotes Endothelial Cell Adhesion and Vascularization

• Recombinant VE-Cadherin, especially when presented as a fusion protein (e.g., with IgG Fc or His-tag), can be used to create artificial extracellular matrices that mimic natural endothelial cell-cell interactions.
• Studies show that surfaces coated with recombinant VE-Cadherin significantly enhance the adhesion, proliferation, and migration of human endothelial cells (such as HUVECs), promoting vascularization in engineered tissues.

2. Supports Functional Studies of Endothelial Junctions

• VE-Cadherin is the primary adhesion molecule at endothelial adherens junctions. Using recombinant VE-Cadherin allows researchers to directly investigate the molecular mechanisms of cell-cell adhesion, barrier function, and junctional stability.
• It enables studies on how VE-Cadherin regulates endothelial permeability, which is critical in understanding vascular leakage, inflammation, and tissue homeostasis.

3. Facilitates Signaling Pathway Analysis

• VE-Cadherin is not only an adhesion molecule but also a signaling hub. It interacts with intracellular proteins such as β-catenin, p120-catenin, and vinculin, and modulates pathways involved in cell survival, proliferation, and cytoskeletal organization.
• Recombinant VE-Cadherin can be used to activate or modulate these signaling pathways in vitro, helping to dissect the role of VE-Cadherin in processes like angiogenesis, lymphangiogenesis, and endothelial barrier regulation.

4. Enables High-Throughput Screening and Drug Discovery

• Recombinant VE-Cadherin can be immobilized on surfaces or used in binding assays to screen for compounds that modulate endothelial adhesion, barrier function, or junctional integrity.
• It is useful for identifying therapeutic agents that target vascular permeability, inflammation, or angiogenesis.

5. Useful for Imaging and Visualization

• Recombinant VE-Cadherin, especially when tagged (e.g., GFP, His-tag), can be used for live-cell imaging and tracking of endothelial junctions in real time.
• It aids in visualizing the dynamics of adherens junctions during processes such as wound healing, inflammation, and vascular remodeling.

6. Relevant to Disease Models

• VE-Cadherin is implicated in various pathological conditions, including cardiovascular diseases, cancer, diabetic retinopathy, and inflammatory disorders.
• Recombinant VE-Cadherin can be used to model disease states, study the effects of soluble VE-Cadherin (sVE-Cadherin) on endothelial barrier breakdown, and investigate the role of VE-Cadherin in tumor angiogenesis and metastasis.

7. Standardization and Reproducibility

• Recombinant proteins provide a consistent and well-characterized source of VE-Cadherin, ensuring reproducibility across experiments and laboratories.
• This is particularly important for comparative studies, quality control, and regulatory applications.

In summary, recombinant human VE-Cadherin is a versatile and essential reagent for studying endothelial cell biology, vascular development, and disease mechanisms. Its ability to promote cell adhesion, modulate signaling, and serve as a tool for imaging and screening makes it indispensable in both basic and applied research.

Yes, recombinant human VE-Cadherin can be used as a standard for quantification or calibration in ELISA assays, provided it is highly purified and its concentration is accurately known. This approach is widely accepted in research ELISA protocols for quantifying target proteins.

Essential context and best practices:

• Standard Curve Preparation: ELISA quantification relies on a standard curve generated from known concentrations of the target protein. Recombinant proteins, such as recombinant human VE-Cadherin, are commonly used for this purpose when native protein standards are unavailable or impractical.
• Purity and Quantification: The recombinant protein must be highly purified and its concentration precisely determined, typically by spectrophotometric methods or amino acid analysis, to ensure accurate calibration.
• Parallelism: It is important to verify that the recombinant standard behaves similarly to the native protein in your assay. Many commercial ELISA kits report that curves generated with recombinant VE-Cadherin are parallel to those obtained with native protein, indicating suitability for quantification.
• Validation: Confirm that your ELISA antibodies recognize both recombinant and native forms of VE-Cadherin with similar affinity. This is usually the case for well-designed sandwich ELISAs, but should be validated for custom assays.
• Concentration Range: Prepare serial dilutions of the recombinant standard covering the expected concentration range in your samples. Typical detection ranges for VE-Cadherin ELISAs are from low pg/mL to ng/mL levels.

Additional considerations:

• Research Use Only: Recombinant standards and ELISA kits are for research use only and not for diagnostic or therapeutic procedures.
• Documentation: Record the lot number, purity, and quantification method of your recombinant standard for reproducibility and transparency.

Summary Table: Recombinant VE-Cadherin as ELISA Standard

In conclusion, recombinant human VE-Cadherin is suitable as a standard for ELISA quantification, provided you follow best practices for standard preparation and assay validation.

Recombinant Human VE-Cadherin protein has been validated for several key applications in published research, primarily related to its role in endothelial cell biology, cell adhesion, and signaling. Based on the provided search results and scientific literature, the following applications have been demonstrated:

1. Cell Adhesion and Aggregation Assays

   • Recombinant VE-Cadherin has been used to study calcium-dependent, homophilic cell-to-cell adhesion and aggregation in transfected cell lines. Studies show that VE-Cadherin expression confers adhesive properties and reduces intercellular permeability, supporting its role in endothelial junction formation and stability (Ref. 2).

2. Permeability Assays

   • The protein has been validated in assays measuring endothelial barrier function and permeability. Transfection of VE-Cadherin into cells results in a significant decrease in permeability to high-molecular-weight molecules, demonstrating its importance in maintaining endothelial integrity (Ref. 2).

3. Signal Transduction Studies

   • Recombinant VE-Cadherin has been used to investigate its role in signaling pathways, including BMP (bone morphogenetic protein) and VEGF (vascular endothelial growth factor) pathways. Studies have shown that VE-Cadherin acts as a positive regulator of BMP signal transduction and modulates VEGF receptor functions (Ref. 4, 5).

4. Western Blotting and Immunoprecipitation

   • The protein is suitable for Western blotting and immunoprecipitation, allowing researchers to detect and quantify VE-Cadherin expression and its interactions with other proteins, such as catenins and polarity complex components (Ref. 2, 5).

5. ELISA and SDS-PAGE

   • Recombinant VE-Cadherin is validated for use in ELISA and SDS-PAGE, enabling quantification and analysis of protein purity and molecular weight (Ref. 3, 14).

6. Flow Cytometry and Immunofluorescence

   • Antibodies against VE-Cadherin, often used in conjunction with recombinant protein, have been validated for flow cytometry and immunofluorescence, allowing for the detection and localization of VE-Cadherin in endothelial cells (Ref. 8, 12).

7. Proximity Ligation Assay (PLA)

   • Recombinant VE-Cadherin has been used in proximity ligation assays to study protein-protein interactions at cell junctions, such as interactions with BMP receptors and other signaling molecules (Ref. 4).

8. Functional Studies in Endothelial Cell Migration and Proliferation

   • The protein has been used to assess its impact on endothelial cell migration, proliferation, and apoptosis, highlighting its role in vascular development and stability (Ref. 5).

These applications underscore the versatility of recombinant human VE-Cadherin in studying endothelial cell biology, vascular development, and disease mechanisms.

To reconstitute and prepare Recombinant Human VE-Cadherin protein for cell culture experiments, follow these general guidelines based on manufacturer protocols and best practices:

1. Reconstitution

• Reconstitution Buffer: Most recombinant VE-Cadherin proteins (especially those with His-tag or Fc-tag) are lyophilized and should be reconstituted in sterile PBS (phosphate-buffered saline, pH 7.4). Some products may recommend sterile distilled water, but PBS is preferred for stability and compatibility with cell culture.
• Concentration: Typical reconstitution concentrations are:
  • 250 µg/mL (e.g., R&D Systems 8440-VC)
  • 100 µg/mL (e.g., R&D Systems 938-VC)
  • Always check the product datasheet for the recommended concentration.
• Procedure:
  • Briefly centrifuge the vial before opening.
  • Add the appropriate volume of sterile PBS to achieve the desired concentration.
  • Gently swirl or pipette up and down to dissolve the protein. Avoid vigorous shaking to prevent foaming and denaturation.
  • Allow the solution to sit at room temperature for 10–15 minutes to ensure complete dissolution.

2. Aliquoting and Storage

• Aliquot: Divide the reconstituted protein into small, single-use aliquots to avoid repeated freeze-thaw cycles, which can degrade the protein.
• Storage:
  • Short-term: Store aliquots at 4°C for up to 1 week.
  • Long-term: Store aliquots at –20°C or –80°C for several months. Use a manual defrost freezer to minimize temperature fluctuations.

3. Preparation for Cell Culture

• Dilution: Dilute the reconstituted VE-Cadherin protein to the desired working concentration in cell culture medium or PBS, depending on the application (e.g., coating surfaces, adding to culture medium).
• Sterility: Ensure all solutions and containers are sterile to prevent contamination.
• Application:
  • For coating surfaces: Incubate the diluted protein on tissue culture plates or coverslips at 4°C overnight or at 37°C for 1–2 hours. Wash with PBS before seeding cells.
  • For soluble protein addition: Add the diluted protein directly to the culture medium at the desired concentration.

4. General Tips

• Avoid repeated freeze-thaw cycles: This can lead to loss of activity and aggregation.
• Check for aggregation: If the solution appears cloudy or has precipitates, centrifuge briefly before use.
• Optimize concentration: The optimal concentration for your experiment may vary. Start with the manufacturer’s recommendation and adjust based on your results.

Example Protocol (R&D Systems 8440-VC)

1. Reconstitute the lyophilized protein in sterile PBS to a concentration of 250 µg/mL.
2. Gently mix and let sit at room temperature for 10–15 minutes.
3. Aliquot into small volumes and store at –20°C.
4. For cell culture, dilute to the desired concentration in PBS or culture medium.
5. Coat surfaces or add to culture as needed.

Always refer to the specific product datasheet for detailed instructions and any unique requirements for your recombinant VE-Cadherin protein.