Recombinant Human GALP Protein: Handling & Usage Protocol

Recombinant Human GALP Protein is a research-grade galanin-like peptide expressed for use in neuroendocrine signaling studies, energy homeostasis research, and receptor-binding assays.

Product Name

Recombinant Human GALP Protein

SKU

rp367905

Source / Origin

Recombinant, expressed in a heterologous host system

Biological Activity

Galanin-like peptide; implicated in regulation of energy balance, reproductive function, and neuroendocrine signaling

Recommended Storage

-20°C to -80°C; avoid repeated freeze-thaw cycles

Application

In vitro bioassays, receptor-binding studies, Western blot, ELISA, cell-based assays

Background: GALP Biology and Research Significance

Galanin-Like Peptide (GALP) is a neuropeptide that shares partial sequence homology with galanin and is predominantly expressed in the hypothalamus. GALP acts through galanin receptors (GalR1, GalR2, and GalR3) and plays important roles in the regulation of energy homeostasis, food intake, body weight, and reproductive neuroendocrine function.

Recombinant Human GALP Protein (SKU: rp367905) provides researchers with a well-characterized reagent for investigating GALP-mediated signaling pathways, receptor pharmacology, and downstream metabolic effects. Its availability as a recombinant protein ensures batch-to-batch consistency critical for reproducible experimental outcomes.

Reconstitution and Buffer Preparation

Follow the steps below to reconstitute Recombinant Human GALP Protein correctly:

1. Centrifuge briefly: Spin the vial at low speed (approximately 1,000 × g for 30 seconds) before opening to consolidate the lyophilized powder at the bottom.
2. Add sterile reconstitution buffer: Reconstitute in sterile phosphate-buffered saline (PBS, pH 7.2–7.4) or the buffer specified on the product datasheet. Use the volume indicated on the Certificate of Analysis (CoA) to achieve the desired stock concentration.
3. Gentle mixing: Do not vortex. Gently pipette up and down or swirl until fully dissolved. Allow 5–10 minutes for complete dissolution at room temperature.
4. Carrier protein addition (optional): For long-term stability and to prevent adsorption to tube surfaces, consider adding bovine serum albumin (BSA) to a final concentration of 0.1% (w/v).
5. Aliquot immediately: Prepare single-use aliquots to minimize freeze-thaw cycles, which can reduce protein activity.

Note: Always consult the product-specific CoA provided with each lot for precise reconstitution instructions, as volumes and concentrations may vary.

Storage, Stability, and Handling Precautions

Short-term storage: Reconstituted protein can be stored at 2–8°C for up to 7 days when carrier protein (BSA) is added.

Long-term storage: For storage beyond one week, aliquot and freeze at -20°C or -80°C. Storage at -80°C is preferred for maximum longevity.

Freeze-thaw cycles: Limit to no more than 3 freeze-thaw cycles. Each cycle may result in measurable loss of biological activity. Use single-use aliquots to mitigate this risk.

General precautions:

• Handle on ice during experimental setup to preserve activity.
• Use low-binding microcentrifuge tubes to minimize adsorptive losses.
• Avoid prolonged exposure to room temperature.
• Do not use if the solution appears turbid or if particulates are visible.

Review_flag: Specific shelf-life data and freeze-thaw tolerance numbers should be verified against the lot-specific CoA provided with SKU rp367905.

Quality Control and Verification

Before initiating experiments, verify the integrity and activity of the Recombinant Human GALP Protein lot using the following approaches:

1. SDS-PAGE / Western Blot: Run a reducing SDS-PAGE gel to confirm the apparent molecular weight of the recombinant protein. Compare with the expected molecular weight reported on the CoA. Western blot using an anti-GALP antibody can confirm identity.

2. ELISA: A sandwich ELISA or competitive ELISA using validated anti-GALP antibodies can quantify protein concentration and verify immunoreactivity.

3. Bioactivity assay: Verify functional activity through receptor-binding assays or cell-based reporter assays employing galanin receptor-expressing cell lines. Dose-response curves should be generated to determine the effective concentration (EC50) for your specific assay system.

4. Endotoxin testing: Confirm that endotoxin levels are below the threshold acceptable for your assay system (typically <1.0 EU/μg for cell-based assays). Check the CoA for lot-specific endotoxin data.

Review_flag: EC50 values and endotoxin specification limits for SKU rp367905 should be verified from the official product CoA and datasheet; no specific numbers have been sourced from the supplied source material.

Experimental Applications and Working Concentration Guidelines

Recombinant Human GALP Protein is suitable for a range of in vitro and cell-based experimental applications. Recommended starting concentrations are provided as general guidelines; optimization for your specific assay is essential.

Application	Suggested Starting Concentration	Notes
Receptor-binding assay	1–100 nM	Titrate against GalR1/2/3 expressing cells or membranes
Cell-based functional assay	10–1000 nM	Monitor downstream signaling (e.g., cAMP, Ca2+ flux)
ELISA (standard curve)	Per kit instructions	Confirm immunoreactivity with validated antibody pair
Western Blot (positive control)	50–200 ng/lane	Use under reducing conditions

Tip: Always include a no-protein negative control and, where possible, a reference standard from a previous validated lot to benchmark inter-lot variability.

Review_flag: Working concentration ranges above are general textbook-level guidance; lot-specific recommended concentrations should be confirmed from the rp367905 product datasheet.

Frequently asked questions

How should I reconstitute Recombinant Human GALP Protein (rp367905)?

Briefly centrifuge the vial before opening, then reconstitute in sterile PBS (pH 7.2–7.4) or the buffer specified on your CoA. Gently pipette to mix—do not vortex—and allow 5–10 minutes for complete dissolution. Aliquot immediately for single-use to avoid repeated freeze-thaw cycles.

What are the recommended storage conditions to maintain GALP protein activity?

Store lyophilized protein at -20°C to -80°C. After reconstitution, aliquot and store at -80°C for long-term use or at 2–8°C for up to 7 days (with carrier protein added). Limit freeze-thaw cycles to a maximum of three to preserve biological activity.

Which experimental applications is Recombinant Human GALP Protein validated for?

Recombinant Human GALP Protein is suitable for receptor-binding assays (using GalR1, GalR2, or GalR3 expressing systems), cell-based functional assays monitoring cAMP or calcium flux, ELISA, and Western blot as a positive control. Always verify lot-specific validation data on the CoA supplied with SKU rp367905.

What does GALP stand for, and why is it important in research?

GALP stands for Galanin-Like Peptide. It is a hypothalamic neuropeptide that signals through galanin receptors (GalR1–3) and is implicated in regulating energy homeostasis, food intake, body weight, and reproductive neuroendocrine function, making it a key target in metabolic and reproductive biology research.

How can I verify the quality of each lot of Recombinant Human GALP Protein?

Confirm protein identity and molecular weight by SDS-PAGE and Western blot using an anti-GALP antibody. Validate immunoreactivity by ELISA and assess functional activity via receptor-binding or cell-based bioassays. Check the lot-specific CoA for endotoxin levels, purity percentage, and any reported EC50 values.

References

1. Larm JA, Gundlach AL. Galanin-like peptide (GALP) mRNA expression is restricted to arcuate nucleus of hypothalamus in adult male rat brain. Neuroendocrinology. 2000;72(2):67–71.
2. Ohtaki T, et al. Isolation and cDNA cloning of a novel galanin-like peptide (GALP) from porcine hypothalamus. J Biol Chem. 1999;274(52):37041–37045.
3. Fraley GS, et al. Galanin-like peptide (GALP) and the role of GALP-synthesizing neurons in the control of body weight and reproduction. Endocrinology. 2004;145(11):4871–4878.

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