Recombinant Mouse ALK-1

Recombinant Mouse ALK-1 is used in research applications to study the molecular mechanisms of vascular development, angiogenesis, and related pathologies, as it is a critical receptor in the TGF-β signaling pathway and regulates endothelial cell function, vessel formation, and immune cell differentiation.

Key reasons to use recombinant Mouse ALK-1 in research include:

• Modeling Vascular Biology and Disease: ALK-1 (also known as ACVRL1) is essential for blood vessel development and maintenance. Mutations or altered signaling are linked to vascular disorders such as hereditary hemorrhagic telangiectasia (HHT) and arteriovenous malformations (AVMs). Recombinant ALK-1 enables in vitro and in vivo studies of these processes, including endothelial cell migration, angiogenic sprouting, and vessel stabilization.

• Angiogenesis and Endothelial Cell Function: ALK-1 signaling modulates the balance between tip and stalk cell phenotypes during angiogenic sprouting. Activation of ALK-1 inhibits excessive sprouting and promotes vessel maturation, making recombinant ALK-1 valuable for dissecting angiogenic mechanisms and screening for modulators of vascular growth.

• Immunomodulation and Tumor Microenvironment: Recent studies show ALK-1 influences the differentiation of bone marrow progenitors into monocytes and macrophages, impacting immune cell recruitment and function in cancer and inflammation. Recombinant ALK-1 can be used to probe these pathways in cell-based assays.

• Protein-Protein Interaction and Ligand Binding Studies: Recombinant ALK-1 is used to characterize interactions with ligands such as BMP9 and BMP10, and with co-receptors like endoglin, which are central to TGF-β/BMP signaling. This is critical for understanding receptor activation, downstream signaling, and therapeutic targeting.

• Functional Assays and Drug Screening: Recombinant ALK-1 is suitable for bioassays measuring ligand-induced signaling (e.g., SMAD phosphorylation, alkaline phosphatase activity), and for screening inhibitors or agonists that modulate ALK-1 activity.

• Species-Specific Studies: Mouse ALK-1 shares significant homology with human ALK-1, but recombinant mouse protein is preferred for studies in murine models to ensure species compatibility and physiological relevance.

• High Purity and Defined Activity: Recombinant preparations are typically >95% pure and endotoxin-free, ensuring reproducibility and minimizing confounding effects in sensitive biological assays.

In summary, recombinant Mouse ALK-1 is a versatile tool for dissecting vascular signaling, modeling disease, and developing therapeutic strategies targeting angiogenesis and immune modulation.

You can use recombinant Mouse ALK-1 as a standard for quantification or calibration in ELISA assays, provided the recombinant protein is of high purity and its concentration is accurately determined. This approach is widely accepted for generating standard curves in quantitative ELISA protocols.

Essential context and supporting details:

• Standard Curve Preparation: ELISA kits for Mouse ALK-1 typically include a recombinant Mouse ALK-1 standard, which is serially diluted to generate a standard curve for quantification. The concentration of unknown samples is interpolated from this curve.
• Recognition of Recombinant Protein: Most commercial Mouse ALK-1 ELISA kits are validated to detect both natural and recombinant Mouse ALK-1, ensuring compatibility for quantification.
• Purity and Activity: The recombinant protein should be highly purified (commonly >95% by SDS-PAGE) and biologically active, as impurities or degradation can affect quantification accuracy.
• Calibration Requirements: If using recombinant Mouse ALK-1 not supplied with a kit, ensure its concentration is precisely measured (e.g., by HPLC or spectrophotometry) and that it matches the epitope recognized by the ELISA antibodies. Some manufacturers note that proteins not calibrated for ELISA must be validated against a mass-calibrated standard.
• Assay Range and Sensitivity: Confirm that the concentration range of your recombinant standard matches the dynamic range and sensitivity of your ELISA assay (e.g., 46.9 pg/ml – 3000 pg/ml).

Best practices:

• Use the same buffer and diluent for both standards and samples to minimize matrix effects.
• Run a standard curve with each assay to account for potential variability.
• Validate the recombinant standard in your specific ELISA system, especially if using a custom or non-kit protein.

Limitations:

• Some ELISA kits may not recommend using recombinant proteins as standards for detection of endogenous proteins due to possible differences in post-translational modifications or epitope presentation. Always consult the specific kit documentation.
• If the recombinant protein differs structurally from the endogenous protein (e.g., fusion tags, truncations), quantification may be affected.

In summary, recombinant Mouse ALK-1 is suitable as a standard for ELISA quantification if it is pure, accurately quantified, and recognized by the assay antibodies. Always validate its performance in your assay system.

Recombinant Mouse ALK-1 has been validated in published research for the following applications:

• Inhibition of BMP-9-induced alkaline phosphatase production: The protein's activity has been measured by its ability to inhibit recombinant human BMP-9-induced alkaline phosphatase production in ATDC5 mouse chondrogenic cells, a standard assay for assessing BMP pathway modulation. This demonstrates its functional utility in studying BMP signaling and ALK1-mediated responses in vitro.

These findings are supported by product details and research protocols, confirming its use in functional assays related to BMP signaling and ALK1 activity.

To reconstitute and prepare Recombinant Mouse ALK-1 protein for cell culture experiments, dissolve the lyophilized protein in sterile, endotoxin-free PBS (phosphate-buffered saline) to a concentration of at least 100 μg/mL. Use aseptic technique throughout the process to maintain sterility.

Step-by-step protocol:

• Centrifuge the vial briefly to ensure all lyophilized powder is at the bottom before opening.
• Add sterile PBS (pH 7.2–7.3, without calcium or magnesium) to achieve the desired concentration (≥100 μg/mL is recommended for stock solutions).
• Gently mix by pipetting up and down or by gentle vortexing until the protein is fully dissolved. Avoid vigorous agitation to prevent protein denaturation.
• Allow the solution to sit for at least 10 minutes at room temperature with gentle agitation to ensure complete dissolution.
• Aliquot the reconstituted protein to minimize freeze-thaw cycles, which can degrade protein activity.
• Storage after reconstitution:
  • Short-term: Store at 2–8 °C for up to 1 month.
  • Long-term: Store at –20 °C to –70 °C for up to 3 months.
  • Avoid repeated freeze-thaw cycles.

Preparation for cell culture:

• Before adding to cells, dilute the stock solution in cell culture medium to the desired working concentration (typically in the range of 10–100 ng/mL, depending on experimental requirements and biological activity).
• Ensure the final solution is sterile and compatible with your cell culture system (e.g., serum-free or phenol red-free media if required for your assay).
• If necessary, filter the final working solution through a 0.2 μm sterile filter to remove any particulates.

Additional notes:

• Always consult the lot-specific datasheet or certificate of analysis for precise instructions and recommended concentrations, as protein formulations and activity may vary between batches.
• If the protein is supplied with an Fc tag or other fusion, confirm compatibility with your assay and cell type.
• For sensitive applications, confirm endotoxin levels are below 0.1 EU/μg to avoid confounding cellular responses.

This protocol ensures optimal solubility, stability, and biological activity of recombinant Mouse ALK-1 protein for cell culture experiments.