IGF-1 LR3
Eighty-three residues — a recombinant protein rather than a synthetic peptide, and by some margin the largest molecule in this catalog. Two deliberate changes separate it from the protein it was derived from, and the name records both.
- Class
- Recombinant protein analogue (83 residues)
- Also written
- Long R3 IGF-1; LR3 IGF-1
- Molecular weight
- 9117.6 g/mol
- Molecular formula
- Not stated. Published formulas for this analogue disagree with one another; the mass is well established and the formula is not, so only the mass is given here.
- CAS number
- 946870-92-4
- Appearance
- White lyophilised powder
- Purity specification
- 99%+ by HPLC
- Vial size stocked
- 1 mg
Structure
M F P A M P L S S L F V N + IGF-1 (1–70) with Glu3→Arg
Two modifications, and the name spells out both. Long is the thirteen-residue N-terminal extension shown above, derived from methionyl porcine growth hormone. R3 is the substitution of arginine for the glutamate at position 3 of the native sequence. 70 + 13 = 83 residues. Three disulphide bonds fold the IGF-1 portion; this is a protein with tertiary structure, not a linear chain.
Origin
Insulin-like growth factor 1 is a 70-residue protein encoded in the human genome. This analogue is not extracted from anything — it is expressed recombinantly, usually in E. coli, and purified. The two modifications were engineered; neither occurs naturally.
Solubility
Sparingly soluble in plain water and readily soluble in dilute acid — weak acetic acid is the conventional first step, with dilution into buffer afterwards. This is the one item in the catalog where a straight water reconstitution may leave visible material undissolved, and that is chemistry rather than a defect.
Storage and handling
- Lyophilised powder: store at −20 °C, protected from light and moisture.
- A folded protein is far more fragile than a short peptide. Do not vortex, do not shake, and keep it cold once in solution.
- Three disulphide bonds hold the fold. Keep reducing agents away from it unless denaturation is the intent.
- Avoid repeated freeze-thaw cycles absolutely; aliquot before the first freeze.
- Label every reconstituted vial with compound, lot, concentration and date.
How your lot is verified
An independent third-party laboratory tests the material first, then we test it again in-house when it arrives — purity by HPLC, identity by mass spectrometry — and only then does it ship. How we verify.
Supplied for laboratory research use only. Not for human or veterinary use. No statement on this page has been evaluated by the Food and Drug Administration, and nothing here is intended to diagnose, treat, cure, or prevent any disease. Alpha Aminos is a chemical supplier and does not provide guidance on the use of any compound.