Background & Biological Significance

ATP10B (ATPase Phospholipid Transporting 10B) is a member of the P4-ATPase subfamily of P-type ATPases, a group of enzymes that catalyze the ATP-dependent translocation of phospholipids from the exoplasmic to the cytoplasmic leaflet of cellular membranes, thereby maintaining membrane lipid asymmetry. This asymmetry is critical for cellular signaling, vesicular trafficking, and apoptotic signaling cascades.

Human ATP10B has been identified as a lysosome-localized flippase with substrate specificity for glucosylceramide and phosphatidylcholine. Emerging evidence links ATP10B to neuroprotective mechanisms, with genetic variants associated with Parkinson's disease susceptibility. Recombinant Human ATP10B Protein (rp366383) enables in vitro investigation of these functions without reliance on endogenous expression systems.

Reagents, Equipment & Safety

Reagents required:

• Recombinant Human ATP10B Protein (rp366383, Aladdin Scientific)
• Reconstitution buffer (manufacturer-recommended; typically PBS pH 7.4 or a buffer specified on the Certificate of Analysis)
• Protease inhibitor cocktail (optional, for downstream assays)
• BSA (for standard curve if applicable)

Equipment required:

• Calibrated micropipettes and low-binding microcentrifuge tubes
• Microcentrifuge capable of ≥10,000 × g
• -80°C freezer and dry ice for handling
• Spectrophotometer or fluorometer (for activity/binding assays)

Safety: Handle according to standard laboratory biosafety practices for recombinant proteins (BSL-1). Wear appropriate PPE including gloves and lab coat. Refer to the product Safety Data Sheet (SDS) for full hazard information. This product is for research use only (RUO) and is not intended for diagnostic or therapeutic applications.

Reconstitution & Storage Protocol

Step 1 – Equilibration: Remove the vial from -80°C storage and allow it to equilibrate briefly on ice (approximately 1–2 minutes). Do not thaw at room temperature to minimize protein degradation.

Step 2 – Reconstitution: Centrifuge the vial briefly (1,000 × g, 30 seconds) to collect lyophilized material at the bottom. Add the recommended volume of reconstitution buffer (refer to the Certificate of Analysis supplied with lot rp366383) slowly along the vial wall. Gently swirl — do not vortex — until fully dissolved. Allow 10 minutes on ice for complete solubilization.

Step 3 – Quality check: Verify clarity of the solution. A turbid or particulate solution may indicate improper reconstitution; centrifuge at 10,000 × g for 5 minutes at 4°C and use the supernatant.

Step 4 – Aliquoting: Prepare single-use aliquots in low-binding tubes to prevent repeated freeze-thaw cycles, which can reduce protein activity and integrity.

Step 5 – Storage: Store working aliquots at -80°C. Short-term storage (≤1 week) may be conducted at -20°C. Once thawed, use immediately and discard unused portion; do not refreeze.

Note: Specific buffer composition, protein concentration, and excipients are provided on the lot-specific Certificate of Analysis. Always consult the CoA before use.

Experimental Applications & Assay Guidelines

Recombinant Human ATP10B Protein (rp366383) is suitable for the following research applications:

• ATPase activity assays: Measure inorganic phosphate release using colorimetric (malachite green) or coupled-enzyme assays to characterize ATP hydrolysis kinetics in the presence of relevant phospholipid substrates.
• Lipid flippase reconstitution: Incorporate the protein into proteoliposomes to study directional phospholipid translocation using fluorescently labeled lipid analogs (e.g., NBD-labeled glucosylceramide or phosphatidylcholine).
• Protein–protein interaction studies: Use in pull-down, co-immunoprecipitation, or surface plasmon resonance (SPR) experiments to identify interacting partners relevant to lysosomal membrane biology.
• Western blot / SDS-PAGE validation: Confirm protein integrity and apparent molecular weight by reducing SDS-PAGE followed by Coomassie staining or immunoblotting with an anti-ATP10B antibody.

Optimize protein concentration, buffer conditions, and incubation times empirically for each specific assay format. Pilot experiments with serial dilutions are recommended before committing to large-scale experiments.

Troubleshooting

Problem: Protein precipitates upon reconstitution.
Possible causes: Buffer incompatibility, excessive agitation, or freeze-thaw damage. Solutions: Use the recommended buffer from the CoA; gently swirl rather than vortex; ensure vial was not subjected to multiple freeze-thaw cycles prior to use.

Problem: Low or undetectable ATPase activity.
Possible causes: Protein denaturation, incorrect assay conditions, or inhibitory components in the buffer. Solutions: Verify protein integrity by SDS-PAGE; confirm Mg²⁺ concentration and pH are optimized for P-type ATPase activity; remove potential inhibitors (e.g., EDTA, azide) from assay buffer.

Problem: Unexpected band size on SDS-PAGE.
Possible causes: Incomplete denaturation, glycosylation, or proteolytic degradation. Solutions: Boil sample for 5–10 minutes in reducing loading buffer; compare observed MW with the theoretical MW stated on the CoA; add fresh protease inhibitors during sample preparation.

Problem: Inconsistent results between experiments.
Possible causes: Repeated freeze-thaw cycles, pipetting variability, or lot-to-lot variation. Solutions: Use single-use aliquots; calibrate pipettes regularly; include an internal positive control in each experiment.