Long R3 IGF-1 is an 83-amino-acid IGF-1 analogue with an Arg substitution at position 3 and a 13-residue N-terminal extension. It is not interchangeable with native 70-residue IGF-1.
Evidence at a glance
- The catalog record uses an approximate molecular weight of 9117.5 g/mol for the 83-residue analogue.
- Sequence, disulfide connectivity, folding, aggregation and bioactivity all matter for a recombinant protein.
- A correct intact mass does not establish native-like folding or potency.
Identity record
The name “LR3” encodes two structural changes. A material lacking the extension or carrying native Glu at position 3 is not the same analogue, even if an antibody cross-reacts with both.
Analytical and evidence boundary
Recombinant expression may produce misfolded, clipped or aggregated species. Intact mass and peptide mapping support primary structure, while size-exclusion chromatography and a qualified cell assay address different quality attributes.
Binding-protein resistance is a design rationale, not a blanket claim about potency in every model. Report the assay system, comparator and concentration whenever describing relative activity.
Editorial rule
State the exact material, form, model or population and endpoint supported by the cited record. Do not convert mechanistic plausibility, an animal result, an official finished-drug label or an analytical test into a claim about an unrelated catalog lot.
Sources & editorial method
This article discusses the source records listed below, with the study models and limitations stated alongside the findings. AI-assisted drafting and image generation were used. The reference list identifies the records behind this article; it is not an independent peer review or verification of a supplied catalog lot.
3 linked records are listed in the references below. Read the editorial and AI-assistance policy.
How to interpret this article
Source-checked on 2026-09-02. Null results, sample size, model/population limits and regulatory scope are retained. This is not medical advice, a customer case or validation of a catalog lot.
Research-use boundary: Catalog materials discussed on this website are for laboratory research, development and manufacturing use only, not for human or veterinary use. This content is not medical advice and does not provide administration instructions.
Primary records and authoritative sources
- Recombinant expression of IGF-1 and LR3 IGF-1 in Pichia pastorisBiotechnology study. 2023. PMID 37261455.
- IGF-1 and LongR3 IGF-1 in bovine oocyte maturationComparative 739-COC study with null meiotic/apoptosis results; PMID 33038561.
- Action of long(R3)-IGF-1 on protein metabolism in beef heifersAnimal study. 1999. PMID 10370861.
Continue with structured records
Move from this editorial analysis to the product identity, filtered evidence and controlled terminology behind it.
