Recombinant Rat ALK-7

Recombinant rat ALK-7 (activin receptor-like kinase 7) offers several compelling advantages for metabolic and signaling research applications.

Metabolic Regulation Studies

Rat ALK-7 is particularly valuable for investigating energy homeostasis and metabolic control. ALK-7 functions as a type I serine/threonine kinase receptor for transforming growth factor-β superfamily members, and its primary physiological role is to limit catabolic activities and preserve energy. This makes it an excellent model system for studying how receptor signaling regulates lipolysis, adiposity, and glucose metabolism. Research using recombinant rat ALK-7 has demonstrated that blocking ALK-7 signaling substantially increases lipolysis and promotes fatty acid oxidation, providing insights into obesity-related metabolic disorders.

Signal Transduction Research

Rat ALK-7 is well-characterized for its role in Smad-mediated signaling pathways. The receptor regulates the activation and nuclear localization of Smad2 and Smad3, inducing their transcriptional activity. This makes recombinant rat ALK-7 particularly useful for investigating TGF-β superfamily signaling mechanisms and for developing assays that measure downstream signaling cascade activation.

Ligand-Receptor Interaction Studies

Recombinant rat ALK-7 serves as an excellent tool for characterizing ligand specificity and binding interactions. The receptor responds to multiple ligands including GDF3, activin B, and activin C, allowing researchers to study differential ligand recognition and receptor selectivity. This is particularly valuable for drug discovery and development of receptor antagonists or agonists.

Tissue-Specific Expression Context

Rat ALK-7 expression is restricted to the adult central nervous system, suggesting specialized roles during postnatal maturation and maintenance. This tissue-specific expression pattern makes rat ALK-7 particularly relevant for neurobiological research applications and for understanding how metabolic signaling integrates with neural function.

You can use recombinant Rat ALK-7 protein as a standard for quantification or calibration in your ELISA assays, provided it is sufficiently pure, accurately quantified, and matches the epitope recognized by your assay antibodies.

For reliable quantification in ELISA:

• The standard should be a purified recombinant protein with a known concentration, ideally verified by an orthogonal method such as HPLC or BCA assay.
• The recombinant ALK-7 must contain the relevant epitope(s) recognized by both the capture and detection antibodies in your ELISA. Most commercial recombinant ALK-7 proteins are designed for this purpose, but you should confirm the sequence and tag do not interfere with antibody binding.
• Prepare a standard curve by serially diluting the recombinant protein in the same buffer as your samples, covering the expected concentration range (typically 0–1000 pg/mL for ELISA).
• Store the reconstituted standard at recommended conditions (usually -20°C or -80°C) to maintain stability and activity.

Validation steps:

• Perform a spike and recovery experiment to confirm that the recombinant standard behaves similarly to endogenous ALK-7 in your sample matrix.
• Ensure the standard curve fits the expected model (typically 4-parameter logistic, 4-PL).
• If using a custom or in-house ELISA, additional optimization may be required to confirm linearity, sensitivity, and reproducibility.

Limitations:

• If the recombinant ALK-7 differs in glycosylation or folding from the native protein, this may affect antibody recognition and quantification accuracy.
• Large dilution steps from stock to working concentrations can introduce error; precise pipetting and validation are essential.

In summary, recombinant Rat ALK-7 is suitable as an ELISA standard if it is pure, well-characterized, and validated for your specific assay conditions.

Recombinant Rat ALK-7 has been validated in published research primarily for studies involving metabolic regulation, adiposity, and TGF-β signaling pathways. Key applications include:

• Functional studies of metabolic homeostasis: ALK-7 is implicated in limiting catabolic activities and preserving energy, with research showing its role in regulating adipose tissue metabolism and energy balance.
• Obesity and diabetes models: Neutralizing antibodies and RNAi therapies targeting ALK-7 have been used in mouse models to reduce adiposity, improve glucose tolerance, and enhance insulin sensitivity. These studies validate ALK-7 as a therapeutic target for metabolic disorders.
• Signal transduction assays: ALK-7 has been used to study activation and nuclear localization of Smad2 and Smad3, key mediators in the TGF-β signaling pathway. Recombinant ALK-7 protein enables investigation of downstream transcriptional activity and pathway modulation.
• Ligand-receptor interaction studies: Recombinant ALK-7 is used to validate ligand specificity, such as with Activin E, confirming ALK-7 as a functional type I receptor in TGF-β superfamily signaling.
• Expression and localization studies: Recombinant ALK-7 facilitates detection and quantification in tissues, including the central nervous system and pancreas, supporting research into its developmental and physiological roles.
• Immunoassays and Western blotting: Recombinant ALK-7 serves as a standard or antigen for antibody validation in immunocytochemistry (ICC/IF), immunohistochemistry (IHC/IHC-P), and Western blot (WB) applications.

These applications are supported by multiple published studies and reviews, confirming the utility of recombinant rat ALK-7 in metabolic, signaling, and molecular biology research. If you require protocol details or specific assay recommendations, please specify the intended experimental context.

To reconstitute and prepare Recombinant Rat ALK-7 protein for cell culture experiments, dissolve the lyophilized protein in sterile distilled water or the buffer recommended in the product documentation, typically to a concentration of 0.5 mg/mL or as specified by the manufacturer.

Essential steps and best practices:

• Centrifuge the vial briefly before opening to collect all lyophilized material at the bottom.
• Add sterile distilled water (or the recommended buffer) directly to the vial. For many recombinant proteins, 0.5 mg/mL is a common starting concentration, but always check the Certificate of Analysis (CoA) or product datasheet for specific instructions.
• Gently mix by pipetting or slow inversion. Avoid vigorous shaking or vortexing, which can denature the protein.
• Allow the protein to fully dissolve at room temperature for 15–30 minutes with gentle agitation.
• Dilute to working concentration using cell culture medium or buffer containing a carrier protein (such as 0.1% BSA or 10% FBS) to minimize protein loss due to adsorption to plasticware.
• Filter sterilize the solution if sterility is required and the protein is not already supplied sterile.
• Aliquot and store any unused reconstituted protein at –20 °C to –80 °C for long-term storage. Avoid repeated freeze-thaw cycles by aliquoting into single-use volumes.

Additional considerations:

• If your cell culture system is serum-free or animal protein-free, use a non-animal stabilizer such as trehalose instead of BSA or FBS for dilution and storage.
• For short-term use (up to one week), store the reconstituted protein at 2–8 °C.
• For long-term storage, add a carrier protein or stabilizer, aliquot, and freeze at –20 °C to –80 °C.
• Always consult the specific product datasheet or CoA for any unique requirements or recommended buffers, as some recombinant proteins may require specific pH or salt conditions for optimal stability and activity.

Summary protocol example:

1. Centrifuge vial, add sterile distilled water to achieve 0.5 mg/mL.
2. Gently mix and let dissolve at room temperature for 15–30 minutes.
3. Dilute to desired working concentration in cell culture medium with 0.1% BSA.
4. Use immediately or aliquot and store at –80 °C.

These steps will help ensure the bioactivity and stability of Recombinant Rat ALK-7 protein for your cell culture experiments.