Recombinant Human IMPG1 Protein: Research Use Guide

Recombinant Human IMPG1 Protein is a research-grade recombinant proteoglycan derived from the human interphotoreceptor matrix, produced for use in studies of retinal extracellular matrix biology, photoreceptor maintenance, and related disease mechanisms.

Product Name

Recombinant Human IMPG1 Protein

SKU

rp365292

Protein Family

Interphotoreceptor Matrix Proteoglycan (IMPG)

Species

Human (Homo sapiens)

Primary Application

In vitro research; retinal extracellular matrix studies

Storage Recommendation

Avoid repeated freeze-thaw cycles; refer to product datasheet for specific conditions

Background: IMPG1 and the Interphotoreceptor Matrix

Interphotoreceptor Matrix Proteoglycan 1 (IMPG1), also known as SPACR (sialoprotein associated with cones and rods), is a chondroitin sulfate and keratan sulfate proteoglycan localized to the interphotoreceptor matrix (IPM) that surrounds the inner and outer segments of rod and cone photoreceptors in the vertebrate retina. The IPM is a specialized extracellular matrix compartment critical for photoreceptor survival, the visual cycle, and the exchange of nutrients and signaling molecules between photoreceptors and the retinal pigment epithelium (RPE).

IMPG1 plays a structural role in organizing the IPM and is implicated in maintaining photoreceptor health. Mutations in the IMPG1 gene have been associated with inherited retinal dystrophies, including vitelliform macular dystrophy and autosomal dominant macular degeneration, highlighting its clinical relevance. Recombinant Human IMPG1 Protein provides researchers with a defined, reproducible source of this protein for functional and biochemical studies.

Protein Specifications and Quality Considerations

Recombinant Human IMPG1 Protein (rp365292) is manufactured under controlled conditions to deliver consistent quality for research applications. When evaluating this product, researchers should consider the following specification parameters as detailed in the product datasheet:

• Expression System: The expression host significantly influences post-translational modifications such as glycosylation, which is particularly relevant for proteoglycans like IMPG1 that carry glycosaminoglycan (GAG) side chains. Confirm the expression system from the current datasheet before designing experiments requiring native-like glycosylation.
• Purity: Purity is typically assessed by SDS-PAGE and/or HPLC. Research applications requiring high specificity, such as binding assays or structural studies, demand high-purity preparations.
• Formulation and Buffer: The protein is supplied in a defined buffer to maintain stability. Refer to the product datasheet for the exact formulation, as buffer composition can affect downstream assay compatibility.
• Endotoxin Level: For cell-based or functional assays, low endotoxin content is critical. Verify endotoxin specifications on the current product datasheet.

Always consult the most current version of the product datasheet (absea#PP-865) for validated lot-specific data including molecular weight confirmation, purity percentage, and bioactivity test results.

Reconstitution, Storage, and Handling Protocol

Proper handling of Recombinant Human IMPG1 Protein is essential to preserve biological activity and ensure experimental reproducibility. Follow the guidelines below as a general framework, and always defer to the specific instructions provided in the product datasheet.

Reconstitution

1. Allow the lyophilized protein (if supplied in lyophilized form) to equilibrate to room temperature for approximately 10–15 minutes before opening to prevent condensation-related degradation.
2. Reconstitute using the buffer recommended in the datasheet (typically sterile PBS or a manufacturer-specified buffer). Add diluent slowly along the side of the vial and gently swirl — do not vortex.
3. Allow the solution to stand for 5–10 minutes at room temperature to ensure complete dissolution.
4. If the protein is supplied as a ready-to-use liquid, equilibrate to the working temperature as instructed.

Storage

• Store the reconstituted protein at –20 °C or –80 °C as specified in the datasheet for long-term stability.
• For short-term use (within 1–2 weeks), storage at 4 °C may be acceptable — confirm in the datasheet.
• Add a carrier protein (e.g., 0.1% BSA) if recommended, to prevent adsorption to tube surfaces at low concentrations.

Handling Precautions

• Minimize repeated freeze-thaw cycles (ideally ≤3 times) by preparing single-use aliquots immediately after reconstitution.
• Use low-binding microcentrifuge tubes to reduce protein loss.
• Avoid prolonged exposure to room temperature.

Experimental Applications

Recombinant Human IMPG1 Protein is suited for a range of in vitro research applications. The following uses represent common research contexts; researchers should validate the protein for each specific assay under their own laboratory conditions:

• ELISA and Immunoassay Development: IMPG1 can serve as a standard or coating antigen in sandwich or competitive ELISA formats to detect anti-IMPG1 antibodies or quantify IMPG1 levels in biological samples.
• Antibody Validation: Use as a positive control antigen for Western blot, immunoprecipitation (IP), or immunofluorescence (IF) to validate anti-IMPG1 antibodies, including those relevant to autoimmune retinal disease research.
• Protein–Protein Interaction Studies: IMPG1 interacts with other IPM components. Recombinant IMPG1 can be used in pull-down assays or surface plasmon resonance (SPR) experiments to map binding partners within the extracellular matrix.
• Cell-Based Assays: Supplement cell culture media or coat surfaces to study the effects of IMPG1 on photoreceptor-like cell adhesion, survival, or differentiation in vitro.
• Structural and Biophysical Studies: Characterize IMPG1 domain architecture, glycosaminoglycan chain interactions, or aggregation behavior using techniques such as dynamic light scattering (DLS) or analytical ultracentrifugation.

Note: All applications should be optimized and validated in the user's laboratory. Aladdin Scientific recommends including appropriate positive and negative controls in all assay formats.

Frequently asked questions

What is IMPG1 and why is it important in retinal research?

IMPG1 (Interphotoreceptor Matrix Proteoglycan 1) is a proteoglycan found in the interphotoreceptor matrix of the retina, where it plays a structural role supporting photoreceptor health and function. It is of significant research interest because mutations in the IMPG1 gene are linked to inherited retinal diseases such as vitelliform macular dystrophy, making it a target for understanding disease mechanisms and developing potential therapies.

How should Recombinant Human IMPG1 Protein be stored after reconstitution?

After reconstitution, prepare single-use aliquots and store them at –20 °C or –80 °C as specified in the product datasheet to maintain long-term stability. Avoid repeated freeze-thaw cycles, as these can cause protein aggregation and loss of activity. For short-term use, storage at 4 °C may be acceptable; consult the datasheet for specific guidance.

Which experimental applications is Recombinant Human IMPG1 Protein validated for?

Recombinant Human IMPG1 Protein (rp365292) is suitable for applications including ELISA, antibody validation (Western blot, immunoprecipitation), protein-protein interaction studies, and cell-based assays. Researchers are advised to optimize and validate the protein for each specific application in their own laboratory. Refer to the absea#PP-865 datasheet for confirmed application data.

Does the glycosylation status of recombinant IMPG1 matter for my experiments?

Yes, glycosylation can be highly relevant for IMPG1 because it is a proteoglycan bearing glycosaminoglycan side chains. The glycosylation pattern depends on the expression host system used during production. For experiments requiring native-like glycosylation (e.g., glycan-dependent binding assays), confirm the expression system from the product datasheet and select the appropriate product format for your application.

How can I minimize protein loss when working with Recombinant Human IMPG1 Protein at low concentrations?

To minimize protein loss at low concentrations, use low-binding microcentrifuge tubes and pipette tips, and consider adding a carrier protein such as 0.1% BSA to the working solution if it does not interfere with your assay. Pre-coat tubes and tips with a dilute BSA solution if necessary, and avoid transferring solutions multiple times.

References

1. Aladdin Scientific Product Datasheet: Recombinant Human IMPG1 Protein, absea#PP-865.
2. Acharya S, Bhattacharya S, Bhattacharya SK, et al. Identification and characterization of SPACR: a novel sialoprotein associated with cones and rods. J Biol Chem. 1998.
3. Manes G, Meunier I, Avila-Fernandez A, et al. Mutations in IMPG1 cause vitelliform macular dystrophies. Am J Hum Genet. 2013.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.