IGF-1 LR3

IGF-1 LR3 (Long-[Arg3]-IGF-I) is an 83-amino-acid analogue of human insulin-like growth factor I. It comprises the complete 70-residue IGF-I sequence with glutamate at position 3 replaced by arginine, preceded by a 13-residue N-terminal extension (MFPAMPLSSLFVN), and retains the three intramolecular disulfide bonds of native IGF-I.

The Arg3 substitution and N-terminal extension markedly reduce binding to IGF-binding proteins (IGFBPs) while largely preserving affinity for the type 1 IGF receptor, increasing the proportion of free, receptor-available ligand in culture systems and in vivo. The analogue was originally characterised in cell-based bioassays alongside IGFBP- and receptor-binding measurements, and its solution structure and backbone dynamics have been determined by NMR. It is widely used as a defined IGF-1R agonist in serum-free cell culture and in studies of IGF signalling and IGFBP biology.

Supplied as a lyophilized powder in a sealed vial.

For laboratory research use only. Not for human or veterinary use.