Recombinant Human Galectin-4

Recombinant Human Galectin-4 is a valuable tool for a wide range of research applications due to its well-characterized biological functions and structural properties. Here are several key reasons why you should consider using Recombinant Human Galectin-4 in your research:

1. Well-Defined Biological Functions

• Galectin-4 is a tandem-repeat type galectin with two distinct carbohydrate recognition domains (CRDs), allowing it to bind different sets of carbohydrate ligands simultaneously. This makes it a natural crosslinker, crucial for regulating processes such as:
  • Lipid raft stabilization and protein apical trafficking
  • Cell adhesion, migration, survival, and apoptosis
  • Intestinal inflammation and wound healing
  • Tumor progression and metastasis (with both tumor-suppressive and metastasis-promoting roles depending on cancer type)

2. Relevance in Disease Research

• Galectin-4 is differentially expressed in various cancers (e.g., colorectal, pancreatic, liver, and gastric cancers), making it a potential biomarker and therapeutic target.
• Its role in stabilizing lipid rafts and modulating immune responses is important for understanding cancer biology, inflammation, and immune regulation.

3. High Purity and Reproducibility

• Recombinant Human Galectin-4 is typically produced with high purity (>95%), ensuring reproducible results in binding and bioactivity assays.
• This consistency is essential for reliable experimental outcomes, especially in quantitative assays such as ELISA, Western blotting, and functional studies.

4. Versatile Applications

• Binding Assays: Study interactions with glycoproteins, glycolipids, and other ligands.
• Bioassays: Investigate cell adhesion, migration, apoptosis, and immune modulation.
• Structural Studies: Utilize for X-ray crystallography, SAXS/WAXS, and molecular modeling to understand its structure-function relationships.
• Cell Culture: Use in cell-based assays to examine the effects of Galectin-4 on cell behavior and signaling pathways.

5. Crosslinking and Regulatory Roles

• Due to its ability to crosslink different ligands, Galectin-4 can be used to study the formation of protein and lipid clusters, which are important for cellular organization and signaling.

6. Research in Neurobiology

• Galectin-4 has been shown to promote axon growth and myelination in neurons, making it relevant for studies in neurobiology and nerve regeneration.

7. Standardization and Quality Control

• Recombinant proteins are standardized, allowing for better comparison across different studies and laboratories. This is particularly important for collaborative research and publication.

8. Availability and Support

• Multiple suppliers offer Recombinant Human Galectin-4 with detailed product information, application notes, and technical support, facilitating experimental design and troubleshooting.

In summary, Recombinant Human Galectin-4 is a versatile and well-characterized protein that can significantly enhance your research in areas such as cancer biology, immunology, cell biology, and neurobiology. Its high purity, reproducibility, and diverse biological functions make it an excellent choice for a wide range of experimental applications.

Yes, recombinant human Galectin-4 can be used as a standard for quantification or calibration in ELISA assays, provided it is compatible with the antibodies and assay format. This is a common practice in quantitative ELISA development for measuring both natural and recombinant forms of the protein.

Key considerations and best practices:

• Formulation: Recombinant Galectin-4 is often supplied either carrier-free or with BSA. For use as an ELISA standard, the BSA-containing formulation is generally recommended to improve stability and reduce adsorption losses, unless BSA interferes with your assay.
• Reconstitution: Follow manufacturer instructions for reconstitution, typically in PBS with at least 0.1% serum albumin to maintain protein stability and prevent adsorption to plasticware.
• Calibration Curve: Prepare serial dilutions of the recombinant Galectin-4 standard to generate a standard curve covering the expected detection range of your assay (e.g., 0.31–20 ng/mL or as specified by your kit).
• Antibody Compatibility: Ensure that the ELISA antibodies recognize both recombinant and native Galectin-4. Most commercial kits and custom sandwich ELISAs are validated for both forms, but some kits are designed only for native protein and may not detect recombinant standards.
• Validation: It is good practice to validate the recombinant standard in your specific assay context, especially if using custom antibodies or non-standard sample matrices.

Scientific precedent:
Recombinant galectins, including Galectin-3 and Galectin-4, are routinely used as calibrators in ELISA assays for quantification purposes. The concentration of the recombinant standard is typically determined spectrophotometrically or by amino acid analysis, and serial dilutions are used to establish the calibration curve.

Limitations:

• If your ELISA kit is specifically designed to detect only native Galectin-4, recombinant protein may not be suitable as a standard.
• Differences in glycosylation or folding between recombinant and native proteins (especially if expressed in E. coli) may affect antibody recognition in rare cases; always confirm compatibility with your assay system.

Summary of protocol steps for using recombinant Galectin-4 as an ELISA standard:

1. Reconstitute recombinant Galectin-4 according to supplier instructions.
2. Prepare serial dilutions in assay buffer (e.g., PBS with 0.1% BSA).
3. Add standards to ELISA plate alongside samples.
4. Generate a standard curve and use it to quantify Galectin-4 in unknown samples.

In conclusion:
Recombinant human Galectin-4 is suitable as a standard for ELISA quantification if it is compatible with your assay antibodies and format. Always validate its performance in your specific assay context.

Recombinant Human Galectin-4 has been validated for several key applications in published research, primarily in the fields of immunology, cancer biology, cell biology, and structural biochemistry.

Validated Applications:

• Bioassays: Used to study its binding activity, bioactivity, and functional effects on immune cells, particularly T cells and macrophages in the context of intestinal inflammation and immune regulation.
• Cell Adhesion and Migration Assays: Applied to investigate its role in cell adhesion, migration, and wound healing, especially in gastrointestinal epithelial cells.
• Tumor Biology Studies: Utilized in assays examining its function as a tumor suppressor or promoter, depending on cancer type (e.g., colorectal, pancreatic, liver, lung), including studies of metastasis, cell cycle progression, and apoptosis.
• Structural Characterization: Employed in X-ray crystallography, SAXS/WAXS, molecular modeling, and differential scanning fluorimetry to elucidate its structure and ligand-binding properties.
• Carbohydrate Binding Specificity: Used in column chromatography, surface plasmon resonance, and inhibitory assays to determine its binding specificity for various glycans and natural ligands.
• SDS-PAGE and Protein Controls: Validated as a control protein in SDS-PAGE and other protein characterization protocols.

Supporting Details:

• Immunology: Galectin-4 interacts with CD3 and binds activated T cells, influencing apoptosis and cytokine secretion in models of intestinal inflammation.
• Cancer Research: Its expression and circulating levels are studied as biomarkers in colorectal, hepatocellular, and breast cancers, and it is implicated in regulating Wnt/β-catenin and IL-6/NF-κB/STAT3 signaling pathways.
• Cell Biology: Galectin-4 is involved in lipid raft stabilization, protein apical trafficking, and cross-linking of glycoproteins and glycolipids on cell surfaces.
• Neuroscience: It has been shown to promote axon growth and myelination in neuronal models.
• Protein Chemistry: Recombinant galectin-4 is routinely used for ligand-binding studies and structural analysis, including domain-specific investigations.

Summary Table of Applications

These applications are supported by multiple peer-reviewed studies and reviews, demonstrating the versatility of recombinant human galectin-4 in both basic and translational research.

Reconstitution Guidelines

The reconstitution method for recombinant human galectin-4 depends on the formulation you are using:

With Carrier Protein (BSA): Reconstitute at 50 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin.

Carrier-Free Formulation: Reconstitute at 100 μg/mL in sterile PBS.

Before opening the vial, centrifuge at 3,000 rpm for 5 minutes to ensure all lyophilized material is at the bottom of the tube. Avoid vortexing the reconstituted solution, as this can cause protein denaturation.

Formulation Selection for Cell Culture

For cell or tissue culture applications, the carrier protein-containing formulation is recommended. The bovine serum albumin carrier enhances protein stability, increases shelf-life, and allows storage at more dilute concentrations. The carrier-free version should only be used when the presence of BSA would interfere with your specific experimental application.

Storage and Stability

After reconstitution, store the protein solution appropriately based on your timeline:

• Short-term storage (2-7 days): 4-8°C
• Long-term storage: -80°C in a manual defrost freezer

Critical: Avoid repeated freeze-thaw cycles, as these significantly reduce protein stability and activity. Aliquot the reconstituted protein into smaller portions to minimize the need for repeated thawing.

Lyophilized protein powder remains stable for 6-12 months when stored desiccated at -20°C to -70°C.

Pre-Experiment Preparation

For cell culture experiments, ensure the reconstituted galectin-4 solution is sterile by filtering through a 0.22 μm syringe filter if not already sterile. Verify the protein concentration using an appropriate quantification method (Bradford, BCA, or absorbance at 280 nm) before use. The recombinant human galectin-4 has a molecular weight of approximately 36 kDa and functions as a tandem-repeat galectin with two carbohydrate recognition domains.