Quantity
Price
$41.00
100 available
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IGF1-LR3
From $41.00to $307.50
For laboratory research use only. Not for human or animal use, consumption, diagnosis, treatment, or disease prevention.
This item is available only through approved account access.
Product Specifications
- Lot Number
- —
- Purity
- —
- Storage Temp
- 36°F to 46°F
For Research Use Only. Not for human or animal administration. Not intended to diagnose, treat, cure, or prevent any disease. Sold for laboratory research purposes only.
Documentation
Certificates of Analysis are supplied with each product lot where applicable.
Certificate of Analysis (COA)
Documentation will be available once product lots are received and tested.
All products currently listed on this site are for research purposes only.
COA Library
Published Certificates of Analysis for IGF1-LR3. New deliveries are added as their batches are released.
No released COA for this strength yet
Reports appear here once a batch for this strength has been released.
Research Data
Chemical & Structural Identifiers
- Chemical Name (IUPAC)
- Recombinant 83-amino-acid analog of human Insulin-Like Growth Factor-1 containing an N-terminal 13-amino-acid peptide extension and an L-arginine substitution at position 3 (Glu3 → Arg3).
- CAS Registry Number
- 946870-92-4 (also cataloged in protein repositories under 167078-06-0).
- PubChem CID
- Biological Macromolecule ID / BioChemEntity.
- Molecular Formula
- C400H625N111O115S9
- Molecular Weight
- 9111.45 Da (9117.50 g/mol average).
- Salt / Counter-Ion
- Supplied as a sterile-filtered, lyophilized powder (acetate salt or carrier-free formulation).
- Synonyms
- IGF1-LR3, Long R3 IGF-1, Long Arg3 IGF-1, Recombinant human Long-R3-IGF-I.
- Disulfide Topology: Three defined intramolecular disulfide bonds (Cys19–Cys34, Cys33–Cys69, Cys68–Cys73).
Analytical & COA Specifications
- Analytical Purity (RP-HPLC / SDS-PAGE)
- ≥ 95.0% (typically ≥ 98.0%) by area normalization under UV detection at λ = 214 nm and Coomassie blue/silver stain densitometry.
- Mass Confirmation (Intact ESI-MS / MALDI-TOF)
- Theoretical deconvoluted mass [M+H]+ = 9118.5 Da; observed mass matches expected multivalent charge envelopes ([M+7H]7+ through [M+11H]11+) within ± 1.0 Da.
- Residual Moisture (Karl Fischer Titration)
- ≤ 3.5% water content.
- Endotoxin Screening (LAL Assay)
- < 1.0 EU/mg (Limulus Amebocyte Lysate per USP <85>).
- Biological Potency (In Vitro ED50)
- ≤ 5.0 ng/mL, quantified via proliferation stimulation assay in serum-free Balb/c 3T3 or FDC-P1 cell lines.
- Physical Characterization
- Dense, white to off-white lyophilized solid cake/powder.
Handling & Stability
Storage. Store dry lyophilized powder desiccated at -20°C to -80°C, protected from atmospheric moisture and direct light.
Solubility. Reconstitute initially in sterile dilute acetic acid (10--100 mM, pH 3.0--4.0) or sterile deionized water at a concentration of ≥ 0.1 mg/mL. Subsequent dilutions into cell culture media should contain 0.1% carrier protein (such as laboratory-grade BSA or HSA) to prevent non-specific surface adsorption.
- Handling Warnings: Contains three tertiary disulfide bridges; *do not* introduce reducing agents (e.g., DTT, TCEP, β-mercaptoethanol) into storage or assay buffers, as reduction of disulfide bonds abolishes tertiary conformation and receptor binding affinity. Avoid vigorous mechanical agitation or vortexing.
Mechanism & Literature
Agonist of the Type 1 Insulin-like Growth Factor Receptor (IGF-1R, a receptor tyrosine kinase), inducing downstream autophosphorylation of the β-subunit kinase domain.
Biochemical Modification Rationale: Engineered to overcome the rapid sequestration of native IGF-1 by Insulin-like Growth Factor-Binding Proteins (IGFBP-1 through IGFBP-6). The Glu3 → Arg3 substitution and the 13-amino-acid N-terminal leader peptide reduce binding affinity for inhibitory IGFBPs by >100-fold while retaining full agonist affinity for the IGF-1R, yielding high free-ligand bioavailability in serum-containing or serum-free in vitro assay systems.
Cellular Pathways Investigated: Extensively documented in in vitro mammalian cell cultures (including C2C12 skeletal myoblasts, primary satellite cells, and CHO bioprocess systems) to analyze IRS-1/PI3K/Akt and Ras/Raf/MAPK/ERK signal transduction, protein synthesis upregulation via mTORC1/p70S6K signaling, and inhibition of apoptosis via Bad/FoxO1 phosphorylation.
References (3)
- Francis, G. L., et al. (1992). Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I: properties of Long R3 IGF-I. Journal of Molecular Endocrinology, 8(3), 213–223.
- Tomas, F. M., et al. (1993). Effects of Long Arg3 insulin-like growth factor-I (LR3IGF-I) in cell culture and biological assay models. Biochemical Journal, 291(3), 781–786.
- Stewart, C. E., et al. (1996). Type I insulin-like growth factor receptor (IGFR) signaling and cell survival in myogenic culture systems. Journal of Cellular Physiology, 169(1), 23–32.
Technical Laboratory FAQs
How does the LR3 structural alteration affect IGFBP binding affinity in vitro?
The combination of the Glu3 → Arg3 amino acid point mutation and the 13-residue N-terminal extension creates steric hindrance and charge alteration at the IGFBP-binding interface, reducing affinity for soluble IGFBPs by more than two orders of magnitude compared to wild-type IGF-1.
Why is an acidic vehicle recommended for initial IGF1-LR3 stock reconstitution?
IGF1-LR3 exhibits optimal solubility and conformational stability in weakly acidic aqueous solutions (pH 3.0--4.0). Reconstituting in neutral, unbuffered aqueous solutions without carrier protein can lead to peptide aggregation or non-specific binding to the walls of glass and plastic labware.
What downstream enzymatic cascades are triggered by IGF1-LR3 in cell culture assays?
IGF1-LR3 binding to the IGF-1R stimulates receptor tyrosine kinase activity, recruiting IRS-1 and activating the PI3K/Akt/mTOR pathway for protein synthesis modeling, as well as the MAPK/ERK pathway for cellular proliferation and survival assays.
For Research Use Only. Not for human or animal administration. Not intended to diagnose, treat, cure, or prevent any disease. Sold for laboratory research purposes only.