What Is HPS4 and Why Is It Important in Research?

HPS4 (Hermansky-Pudlak Syndrome Protein 4) is a subunit of the BLOC-3 (Biogenesis of Lysosome-related Organelles Complex 3) complex. BLOC-3 plays a critical role in the biogenesis of lysosome-related organelles such as melanosomes and platelet dense granules. Loss-of-function mutations in the HPS4 gene cause Hermansky-Pudlak syndrome type 4, a rare autosomal recessive disorder characterized by oculocutaneous albinism, bleeding diathesis, and in some cases pulmonary fibrosis or immune deficiency.

Recombinant Human HPS4 Protein enables researchers to study BLOC-3 complex assembly, protein–protein interactions, and the molecular mechanisms underlying lysosome-related organelle dysfunction, making it a valuable reagent for both basic and translational research programs.

Product Specifications and Quality Information

Recombinant Human HPS4 Protein (SKU: rp375103) is produced as a recombinant protein intended for research use only. Key specification areas to confirm on the official product datasheet include:

• Expression system: Confirm whether the protein is expressed in E. coli, baculovirus/insect cells, mammalian cells, or wheat germ — consult the certificate of analysis (CoA) or datasheet for the specific lot.
• Purity: Typical research-grade recombinant proteins are ≥85–95% pure by SDS-PAGE; verify the exact purity specification on the current CoA.
• Tag information: The protein may carry an affinity tag (e.g., His-tag or GST) to facilitate purification; confirm tag position (N- or C-terminal) before experimental design.
• Formulation: Supplied lyophilized or in liquid buffer; confirm buffer composition, pH, and any carrier protein additions from the datasheet.
• Endotoxin level: Verify endotoxin specification if the protein is to be used in cell-based or in vivo experiments.

Always request the lot-specific CoA from Aladdin Scientific to confirm the most current specifications before placing an order or designing experiments.

Storage, Handling, and Reconstitution Guidelines

Proper storage and handling are essential to preserve the activity and integrity of Recombinant Human HPS4 Protein. General best-practice guidelines are provided below; always defer to the lot-specific datasheet for authoritative instructions:

• Short-term storage: If the protein will be used within days to weeks, store at 4 °C in its supplied buffer.
• Long-term storage: Aliquot upon receipt and store at -80 °C to avoid activity loss from repeated freeze-thaw cycles. Do not store in a frost-free freezer.
• Freeze-thaw cycles: Limit to three or fewer cycles. Prepare single-use aliquots at the volume appropriate for your assay.
• Reconstitution (lyophilized form): Centrifuge the vial briefly before opening. Reconstitute in sterile deionized water or the buffer specified in the datasheet. Allow to dissolve gently; do not vortex vigorously.
• Carrier protein: If the protein is at low concentration, adding BSA (0.1%) to the working solution may help stabilize activity during storage.
• Working concentration: Determine empirically for each assay; typical ranges for binding or enzymatic assays should be validated by the end user.

Research Applications of Recombinant Human HPS4 Protein

Recombinant Human HPS4 Protein is suitable for a variety of in vitro biochemical and cell biology research applications, including but not limited to:

• Protein–protein interaction studies: Investigate HPS4 binding partners within the BLOC-3 complex (notably HPS1) or other interacting proteins using pull-down assays, co-immunoprecipitation, or surface plasmon resonance (SPR).
• Antibody validation: Use as a positive control antigen to validate anti-HPS4 antibodies in Western blot, ELISA, or dot blot applications.
• Biochemical assays: Employ in structural or biophysical studies, including size-exclusion chromatography, native PAGE, or calorimetry experiments to characterize complex formation.
• Disease mechanism research: Support studies of Hermansky-Pudlak syndrome, including lysosomal trafficking, organelle maturation, and potential therapeutic target identification.
• Drug discovery: Use as a target protein in screening assays designed to identify small molecules that modulate BLOC-3 function or HPS4 interactions.

This protein is intended for research use only and is not approved for diagnostic or therapeutic procedures in humans or animals.

Ordering, Regulatory Status, and Customer Support

How to order: Recombinant Human HPS4 Protein (SKU: rp375103) can be ordered directly through the Aladdin Scientific website or by contacting our sales team. When placing an order, specify the required quantity and any special handling requirements for shipping.

Regulatory and intended use: This product is supplied for research use only (RUO). It is not intended for clinical diagnostic use, therapeutic administration, or veterinary application unless explicitly stated otherwise by Aladdin Scientific. Users are responsible for compliance with all applicable local regulations governing the purchase, storage, and use of recombinant proteins.

Returns and technical support: If you have concerns about product quality, activity, or specification discrepancies, contact Aladdin Scientific technical support with your lot number and CoA. Our team can assist with troubleshooting, replacement decisions, and protocol optimization guidance.

Documentation: Safety Data Sheets (SDS) and Certificates of Analysis (CoA) are available upon request or via the product page on the Aladdin Scientific website.