p1,p5-Di(adenosine-5′-)pentaphosphate, trilithium salt

Ap5A (p1,p5-Di(adenosine-5′-)pentaphosphate) is a naturally occurring diadenosine polyphosphate consisting of two adenosine molecules connected by five phosphate groups. It serves multiple important research functions.

Primary research applications:

• Adenylate kinase inhibitor: Competitive inhibitor with Ki ~10 µM, used to study ATP metabolism
• P2 receptor antagonist: Blocks P2Y purinergic receptors, important for studying extracellular signaling
• Platelet aggregation inhibitor: Prevents platelet activation, useful in cardiovascular research
• Enzyme kinetics: Tool for understanding phosphotransferase mechanisms
• Cell signaling: Investigates purinergic signaling pathways

Biological significance: Ap5A is found naturally in cells and is released during stress conditions. It functions as an extracellular signaling molecule and intracellular second messenger, making it valuable for studying both autocrine/paracrine signaling and cellular stress responses.

ChemContract supplies p1,p5-Di(adenosine-5′-)pentaphosphate trilithium salt at ≥95% purity, verified by multiple analytical techniques.

Quality control methods:

• HPLC purity: ≥95% by peak area analysis with UV detection
• ¹H NMR: Confirms adenosine structure and phosphate connectivity
• ³¹P NMR: Verifies five phosphate groups and their linkages
• Mass spectrometry: Molecular weight confirmation (ESI-MS)
• UV-Vis: Spectral properties consistent with adenine chromophore (λmax ~259 nm)

Certificate of Analysis includes:

• Batch number and manufacturing date
• HPLC chromatogram with purity calculation
• ¹H NMR and ³¹P NMR spectra
• Mass spectrum
• Appearance and solubility testing
• Storage recommendations

Proper storage is critical for Ap5A due to its hygroscopic nature and phosphate instability.

Storage conditions:

• Temperature: -20°C (freezer storage)
• Moisture protection: Store in desiccator with desiccant
• Container: Tightly sealed, preferably under argon or nitrogen
• Hygroscopic: Minimize exposure to air during handling
• Shelf life: 24 months when stored properly

Stock solution preparation:

• Solvent: Prepare in deionized water or appropriate buffer
• Concentration: 10-100 mM stock solutions recommended
• pH: Neutral pH (6.5-7.5) for stability
• Storage: Aliquot and freeze at -20°C or -80°C
• Stability: Aqueous solutions stable for several months when frozen
• Avoid: Repeated freeze-thaw cycles

Handling tips:

• Allow vial to warm to room temperature before opening
• Weigh quickly and reseal immediately
• Use dry spatula and weighing paper
• Return to freezer promptly after use

Working concentrations vary by application and should be optimized for each experimental system.

Recommended concentration ranges:

• Adenylate kinase inhibition: 10-100 µM (Ki ~10 µM, use 5-10x Ki)
• P2 receptor studies: 0.1-100 µM (depends on receptor subtype)
• Platelet aggregation: 10-100 µM
• Cell culture experiments: 1-100 µM
• Enzyme assays: 10 µM – 1 mM

Concentration optimization tips:

• Start high: Begin with 100 µM and titrate down
• Dose-response: Test multiple concentrations (e.g., 1, 10, 100 µM)
• Cell type variation: Optimal concentration varies with cell line
• Time course: Effects may be time-dependent, test different incubation times
• Solubility: Ap5A is highly water-soluble, up to >100 mM

Kinetic parameters:

• Ki (adenylate kinase): ~10 µM
• IC₅₀ (platelet aggregation): ~50 µM
• EC₅₀ (P2Y receptors): Variable by receptor subtype

The trilithium salt form offers several advantages over free acid or other salt forms of Ap5A.

Advantages of trilithium salt:

• Enhanced stability: More stable than free acid form during storage
• Better solubility: Highly water-soluble, dissolves readily
• Defined stoichiometry: Known lithium content for accurate molarity calculations
• pH neutral: Less acidic than free acid, gentler on biological systems
• Easy handling: Solid form is easier to weigh and dispense
• Reduced hygroscopicity: Less moisture uptake than some sodium salts

Comparison with other forms:

• Free acid: More hygroscopic, difficult to handle, undefined hydration state
• Sodium salt: More hygroscopic than lithium salt
• Ammonium salt: May interfere with some biological assays

Considerations for use:

• Lithium content is typically low and non-interfering in most assays
• If lithium is a concern for your specific application, verify compatibility
• Calculate molarity based on entire molecular weight including lithium

Yes, Ap5A is membrane-permeable and widely used in cell-based assays to study purinergic signaling, enzyme inhibition, and platelet function.

Cell culture applications:

• P2 receptor studies: Add to culture medium at 1-100 µM
• Platelet studies: Incubate with platelets to inhibit aggregation
• Cell signaling: Monitor calcium mobilization, cAMP levels, etc.
• Stress response: Study cellular responses to purinergic stimulation
• Toxicity studies: Generally non-toxic at working concentrations

Protocol recommendations:

• Preparation: Prepare fresh in culture medium or PBS
• Sterilization: Filter-sterilize (0.22 µm) if sterility required
• Addition: Add directly to culture medium
• Incubation: Pre-incubate 15-30 minutes before stimulation (for antagonist studies)
• Controls: Include vehicle control (water or buffer)

Compatibility:

• Compatible with serum-containing and serum-free media
• No special medium requirements
• Can be combined with other agonists/antagonists
• Minimal interference with most cell culture assays

We offer multiple pack sizes to accommodate different research needs.

Available quantities (in stock):

• 1 mg – For initial studies
• 5 mg – Standard research quantity
• 10 mg – Extended studies
• 25 mg – Large-scale experiments
• Custom quantities: Available upon request

Usage estimates:

• 1 mg = ~1 µmol = enough for 100 assays at 10 µM in 1 mL
• 5 mg = ~5 µmol = enough for 500 assays
• 10 mg = ~10 µmol = extended research programs

Delivery times:

• Stock quantities: Ships within 24-48 hours
• Domestic USA: 2-3 business days (FedEx/UPS)
• International: 5-7 business days (DHL/FedEx)
• Custom quantities: 2-3 weeks

Packaging:

• Shipped with ice packs in insulated container
• Sealed under argon or nitrogen
• Includes desiccant packet
• COA and SDS included