Recombinant Human GGA3 Protein: Handling & Application Protocol
Recombinant Human GGA3 Protein: Handling & Application Protocol
Recombinant Human GGA3 Protein is a critical research reagent for investigating Golgi-localized, gamma-adaptin ear homology domain Arf-binding protein 3 (GGA3) functions in vesicular trafficking, cargo sorting at the trans-Golgi network, and its emerging role in amyloid precursor protein processing relevant to Alzheimer's disease research.
- Product Name
- Recombinant Human GGA3 Protein
- SKU
- rp374695
- Protein Family
- GGA (Golgi-localized, Gamma-adaptin ear homology domain, Arf-binding) family
- Primary Research Application
- Vesicular trafficking, cargo sorting, Alzheimer's disease-related BACE1 regulation
- Recommended Storage
- -80°C for long-term storage; avoid repeated freeze-thaw cycles
- Host Expression System
- To be confirmed with product datasheet (see review flag)
- Purity
- To be confirmed with product datasheet (see review flag)
Background and Biological Significance of GGA3
GGA3 (Golgi-localized, Gamma-adaptin ear homology domain, Arf-binding protein 3) is a monomeric clathrin adaptor protein predominantly localized to the trans-Golgi network (TGN). It belongs to the GGA protein family, which includes GGA1, GGA2, and GGA3, all of which share a conserved domain architecture comprising a VHS (Vps27/Hrs/STAM) domain, a GAT (GGA and Tom1) domain, a hinge region, and a GAE (gamma-adaptin ear homology) domain.
GGA3 plays a pivotal role in the sorting and transport of mannose-6-phosphate receptors (MPRs) and other transmembrane cargo proteins between the TGN and endosomes. Of particular relevance to biomedical research, GGA3 has been implicated in the regulation of BACE1 (beta-site APP cleaving enzyme 1), a key protease in amyloid precursor protein (APP) processing. Dysregulation of GGA3 function has been associated with increased BACE1 levels and elevated amyloid-beta production, linking GGA3 to the pathophysiology of Alzheimer's disease.
Recombinant Human GGA3 Protein (rp374695) enables researchers to study these molecular mechanisms in vitro, perform binding assays, and investigate GGA3 interactions with its known partners including ARF1, clathrin, and ubiquitinated cargo.
Product Specifications and Quality Information
The following specifications are provided as general guidance for Recombinant Human GGA3 Protein (SKU: rp374695). Researchers should always consult the current product datasheet supplied with each lot for confirmed values including purity, specific activity, endotoxin levels, and formulation details.
- Product SKU: rp374695
- Protein: Recombinant Human GGA3
- Expression Host: Confirm with product datasheet
- Tag Information: Confirm with product datasheet
- Formulation/Buffer: Confirm with product datasheet; typically lyophilized or liquid formulations in a stabilizing buffer
- Purity: Confirm with product datasheet
- Endotoxin Level: Confirm with product datasheet
- Storage Temperature: -80°C recommended for long-term storage
Quality control validation typically includes SDS-PAGE analysis for purity confirmation and biological activity assays where applicable. Please contact Aladdin Scientific technical support for lot-specific certificates of analysis.
Reconstitution and Storage Protocol
Proper reconstitution and storage of Recombinant Human GGA3 Protein are essential to maintain protein integrity and experimental reproducibility. Follow these steps carefully:
Reconstitution (for lyophilized format)
- Briefly centrifuge the vial at low speed (e.g., 1,000–2,000 × g for 30 seconds) before opening to collect any residual powder at the bottom.
- Allow the vial to equilibrate to room temperature for approximately 10–15 minutes before opening.
- Reconstitute the lyophilized protein by adding the appropriate volume of sterile, ultrapure water or the buffer specified in the product datasheet. Add the solvent gently along the side of the vial.
- Do not vortex. Gently swirl or pipette to mix until the protein is fully dissolved.
- Allow the solution to stand at room temperature for 5–10 minutes if needed to ensure complete dissolution.
- Prepare working aliquots to avoid repeated freeze-thaw cycles. A carrier protein (e.g., 0.1% BSA) may be added to the diluent to improve stability at low concentrations, if compatible with your assay.
Storage
- Store reconstituted protein aliquots at -80°C for long-term storage (up to the expiry date indicated on the datasheet).
- For short-term use within 1–2 weeks, aliquots may be stored at -20°C or 4°C depending on formulation; confirm with the product datasheet.
- Avoid repeated freeze-thaw cycles as these can lead to protein aggregation, loss of activity, and degraded experimental results.
- Do not store at room temperature for extended periods.
Recommended Applications and Experimental Procedures
Recombinant Human GGA3 Protein is suitable for a range of in vitro biochemical and cell-free applications. The following application guidance reflects standard practices for recombinant adaptor proteins of this class.
1. Protein–Protein Interaction Studies (e.g., Pull-down / Co-IP)
GGA3 is known to interact with ARF GTPases, ubiquitin, and clathrin. To investigate these interactions:
- Use the recombinant GGA3 protein as bait or prey in GST pull-down or His-tag pull-down assays.
- Optimize binding buffer conditions to include physiological salt concentrations (e.g., 150 mM NaCl, 20 mM HEPES pH 7.4) and appropriate detergent if needed.
- Include negative controls (e.g., unrelated recombinant protein of similar molecular weight).
2. ELISA and Antibody Validation
Recombinant GGA3 can be used as a positive control antigen or coating antigen in ELISA formats to validate anti-GGA3 antibodies:
- Coat ELISA plate wells at the concentration recommended in the antibody datasheet (typically 0.1–2 µg/mL).
- Follow standard ELISA blocking and detection protocols.
3. Structural and Biophysical Studies
High-purity recombinant GGA3 protein may be used in biophysical techniques such as surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), or circular dichroism (CD) to characterize domain–ligand interactions and protein folding.
4. Western Blot Positive Control
Load a known quantity of recombinant GGA3 protein (confirm appropriate amount with datasheet) alongside cell lysate samples to serve as a molecular weight marker and signal intensity reference for anti-GGA3 western blots.
Troubleshooting and Technical Tips
The following troubleshooting guidance addresses common challenges encountered when working with Recombinant Human GGA3 Protein.
| Problem | Possible Cause | Recommended Solution |
|---|---|---|
| No detectable signal in activity assay | Protein degradation due to improper storage or freeze-thaw | Use freshly thawed aliquots; verify storage conditions; check expiry date |
| Protein aggregation after reconstitution | Reconstitution performed too rapidly or with incorrect buffer | Reconstitute slowly using recommended buffer; centrifuge briefly after reconstitution to remove aggregates |
| Non-specific bands on Western blot | Protein concentration too high or antibody cross-reactivity | Titrate protein amount; optimize antibody concentration and blocking conditions |
| Weak binding in pull-down assay | Suboptimal buffer ionic strength or pH | Optimize salt concentration and pH; ensure binding conditions match physiological requirements for GGA3 interactions |
| Low signal in ELISA | Coating concentration too low or protein denatured during coating | Increase coating concentration; coat at 4°C overnight instead of at 37°C to preserve native conformation |
For additional technical support, contact Aladdin Scientific customer service or technical support team with your lot number and specific experimental conditions.
Frequently asked questions
What is GGA3 and why is it important in research?
GGA3 (Golgi-localized, Gamma-adaptin ear homology domain, Arf-binding protein 3) is a monomeric clathrin adaptor protein that mediates vesicular trafficking between the trans-Golgi network and endosomes. It is of significant research interest because of its role in regulating BACE1 trafficking, which is directly linked to amyloid-beta production and Alzheimer's disease pathology. GGA3 is also studied in the context of general lysosomal biogenesis and cargo sorting.
How should I reconstitute Recombinant Human GGA3 Protein?
For lyophilized preparations, briefly centrifuge the vial before opening, allow it to reach room temperature, then add the volume of sterile ultrapure water or recommended buffer specified in the product datasheet gently along the vial wall. Do not vortex; instead, gently swirl or pipette to mix. Prepare single-use aliquots immediately after reconstitution to avoid repeated freeze-thaw cycles that can compromise protein integrity.
What applications is Recombinant Human GGA3 Protein (rp374695) suitable for?
Recombinant Human GGA3 Protein is suitable for protein-protein interaction studies (such as pull-down and co-immunoprecipitation assays), ELISA antigen coating and antibody validation, Western blot positive controls, and biophysical characterization techniques including SPR and ITC. Always verify specific validated applications in the current product datasheet, as suitability may vary by lot and format.
How should Recombinant Human GGA3 Protein be stored to maintain stability?
For long-term storage, maintain reconstituted or liquid-format GGA3 protein aliquots at -80°C. Avoid repeated freeze-thaw cycles by preparing small, single-use aliquots at the time of reconstitution. Do not store at room temperature for extended periods. Refer to the product datasheet for formulation-specific storage recommendations and shelf life information.
Can Recombinant Human GGA3 Protein be used in cell-based assays?
Recombinant Human GGA3 Protein is primarily intended for in vitro biochemical applications. Use in cell-based assays (such as protein transfection or microinjection) may be possible but would require additional optimization and validation by the researcher. Check the product datasheet for any validated cell-based application data, and contact Aladdin Scientific technical support for specific guidance.
References
- Bonifacino JS. The GGA proteins: adaptors on the move. Nature Reviews Molecular Cell Biology. 2004;5(1):23–32. doi:10.1038/nrm1279
- Tesco G, Koh YH, Kang EL, et al. Depletion of GGA3 stabilizes BACE and enhances beta-secretase activity. Neuron. 2007;54(5):721–737. doi:10.1016/j.neuron.2007.05.012
- Puertollano R, Aguilar RC, Gorshkova I, Crouch RJ, Bonifacino JS. Sorting of mannose 6-phosphate receptors mediated by the GGAs. Science. 2001;292(5522):1712–1716. doi:10.1126/science.1060750
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.