igf-1 lr3
GH AXIS · IGF-1 ANALOGUE · 83 AA · IGFBP-EVADING
also: LONG R3 IGF-I · Long R3 IGF-1 · LR3 IGF-1
IGF-1 LR3 is an 83-residue recombinant analogue of human IGF-1 carrying a Glu3-to-Arg substitution and a 13-residue N-terminal extension, modifications that give it markedly reduced affinity for IGF-binding proteins and therefore greater free access to the IGF-1 receptor. Its documented use is as a serum-free supplement in mammalian cell culture and bioprocessing; there are no published human clinical trials, and animal studies show it can suppress endogenous GH and IGF-1 and impair beta-cell insulin secretion.
// our evidence grade — unedited
There is not one human clinical trial of IGF-1 LR3 for any indication; the molecule was deliberately engineered to escape the IGF-binding-protein system that normally restrains IGF-1 receptor signalling, it is sold and validated by its manufacturers as a cell-culture reagent whose bioassay is breast cancer cell proliferation, and the epidemiology of the pathway it maximally activates links higher IGF-I to elevated cancer risk.
We grade this compound and we sell it. The grade is set against our published criteria before any stocking decision and is not adjusted because it is in the catalogue.
read the full evidence →// specification
| full name | Long R3 Insulin-like Growth Factor-1 (LONG R3 IGF-I) |
| cas | 946870-92-4 |
| molar mass | 9112 g/mol |
| purity | ≥ 95% (SDS-PAGE / HPLC) |
| form | lyophilised powder, sealed vial |
| storage | Lyophilised protein is stored at -20 °C to -80 °C, desiccated and protected from light; reconstituted solution is used within a short window at 2-8 °C or aliquoted and stored at -20 °C to -80 °C, and repeated freeze-thaw cycles are avoided because the folded three-disulfide protein is prone to aggregation and loss of activity. |
| solubility | Reconstituted in sterile water, or in dilute acid such as 10 mM HCl or dilute acetic acid where a stock above about 100 µg/mL is required, then diluted into buffer; carrier protein is often added in cell-culture use to reduce adsorption losses. |
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crypto payment · research use only · not for human consumption
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