Protein Background and Biological Significance

IGLON5 (IgLON Family Member 5) is a glycosylphosphatidylinositol (GPI)-anchored cell adhesion molecule expressed predominantly in the central nervous system. It belongs to the IgLON subfamily within the broader immunoglobulin superfamily and shares structural features including multiple immunoglobulin-like C2-type domains that mediate homophilic and heterophilic cell–cell interactions.

IGLON5 has attracted significant clinical and research interest following the discovery of anti-IGLON5 autoantibodies in patients presenting with a distinctive syndrome characterized by non-REM and REM sleep parasomnias, bulbar dysfunction, and an underlying tauopathy. This condition, now recognized as IGLON5-related tauopathy (or anti-IGLON5 disease), underscores the protein's importance at the intersection of autoimmunity and neurodegeneration.

Beyond autoimmune contexts, IGLON5 is studied for its roles in axon guidance, synapse formation, and neural circuit development, making Recombinant Human IGLON5 Protein a valuable tool for dissecting these pathways in vitro.

Reconstitution, Handling, and Storage Protocol

Reconstitution: If supplied in lyophilized form, briefly centrifuge the vial before opening to pellet any protein that may have adhered to the cap or sides. Reconstitute in sterile, deionized water or an appropriate buffer (e.g., PBS, pH 7.4) to a concentration of 0.1–1.0 mg/mL. Allow the solution to equilibrate at room temperature for 10–15 minutes with gentle swirling; do not vortex, as this may cause aggregation or denaturation.

Handling precautions: Use low-protein-binding microcentrifuge tubes and pipette tips to minimize adsorption losses. If carrier protein is required for low-concentration working solutions, supplement with 0.1–0.5% BSA (molecular biology grade).

Storage: Aliquot reconstituted protein into single-use volumes to avoid repeated freeze-thaw cycles, which degrade activity. Store aliquots at -80°C for long-term preservation (up to 12 months) or at -20°C for short-term use (up to 1 month). Once thawed, keep on ice and use within the same working session. Do not refreeze.

Note: Always consult the product-specific datasheet provided with SKU rp368300 for lot-specific reconstitution volumes and concentration recommendations.

Recommended Applications and Experimental Considerations

ELISA: Recombinant Human IGLON5 Protein is suitable as a coating antigen or standard for enzyme-linked immunosorbent assays aimed at detecting and quantifying anti-IGLON5 antibodies in serum or cerebrospinal fluid samples. Optimize coating concentrations (typically 1–4 µg/mL) and blocking conditions empirically for your platform.

Western Blot: The recombinant protein can serve as a positive control to confirm antibody specificity in Western blot experiments. Load 50–200 ng per lane alongside cell lysate samples for comparative analysis.

Cell-Based Functional Assays: IGLON5 mediates cell adhesion and neurite outgrowth. Recombinant protein can be adsorbed onto culture substrates or presented in solution to study its effects on neuronal morphology, adhesion, and signaling in primary neuron or neuroblastoma cell cultures.

Antibody Production and Validation: The protein is appropriate for immunization protocols to generate research-grade anti-IGLON5 antibodies, as well as for antibody affinity purification and validation.

General tip: Include appropriate positive and negative controls in every assay. Verify the biological activity of each new lot using a functional assay prior to committing to large-scale experiments.

Quality Control and Purity Considerations

Recombinant proteins intended for research applications should meet defined quality benchmarks. When evaluating Recombinant Human IGLON5 Protein (rp368300), consider the following quality parameters:

• Purity: SDS-PAGE and/or HPLC analysis should confirm purity. Confirm the expected molecular weight band for IGLON5, taking into account any glycosylation that may shift apparent molecular weight on denaturing gels.
• Endotoxin levels: For cell-based assays, endotoxin contamination can confound results. Request the endotoxin specification from the Certificate of Analysis (CoA) and verify it is within acceptable limits for your application (typically <1 EU/µg for sensitive cell assays).
• Biological activity: Where a functional assay is established (e.g., cell adhesion assay), confirm activity on receipt of each lot.
• Protein identity: Mass spectrometry or N-terminal sequencing data on the CoA can confirm identity. Review the CoA provided by Aladdin Scientific for lot-specific data.

Always request the Certificate of Analysis for lot rp368300 before use, and archive it with your experimental records for traceability and regulatory compliance.