Loading…
For laboratory research use only. Not for human or veterinary use.
Loading…
Recombinant IGF-I analogue
Also catalogued as Long R3 IGF-1, Long [Arg3] insulin-like growth factor-I, LR3-IGF-I.
Eighty-three residues against the seventy of human IGF-I: a thirteen-residue extension MFPAMPLLSLFVN at the N-terminus, and arginine substituted for glutamate at position 3 of the IGF-I chain — the two changes the name records as “Long” and “R3”. The full sequence is not reproduced here because the published record for it was not verified, and the three disulfide bridges it folds into are not expressible in one-letter code in any case.
IGF-1 LR3 is an engineered analogue of human insulin-like growth factor I, a 70-residue single-chain protein of the insulin superfamily. Two deliberate changes distinguish it: a thirteen-residue peptide extension added to the N-terminus, and a single substitution of arginine for the glutamate at position 3.
The analogue was described by Francis and colleagues in 1992, among a set of recombinant IGF-I variants expressed in Escherichia coli as fusion proteins. It is produced recombinantly rather than by solid-phase synthesis, which is what the chain length makes practical.
IGF-1 LR3 is a research reagent. It is not an approved drug in any jurisdiction.
Francis GL, Ross M, Ballard FJ, et al. Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I indicate the relative importance of IGF-binding protein and receptor binding for enhanced biological potency. Journal of Molecular Endocrinology 1992;8(3):213–223.
Citation titles are reproduced verbatim from the journal record. A citation documents the molecule's published identity and history; it is not a claim about the material sold here.