IGF-1 LR3 Research Overview

IGF-1 LR3 Research Overview

IGF-1 LR3, or Long R3 Insulin-like Growth Factor-1, is an 83-amino-acid modified analog of native IGF-1. It combines a 13-amino-acid N-terminal extension with an arginine substitution at position 3. These structural changes reduce affinity for insulin-like growth factor binding proteins (IGFBPs), making LR3 a useful reference material for controlled studies of sustained IGF-1 receptor signalling.

Researchers sourcing the compound can review the IGF-1 LR3 research material, its listed specifications, and the available batch-verification pathway.

Structural identity

Native IGF-1 contains 70 amino acids. LR3 contains 83 amino acids because of its N-terminal extension, and the Arg3 substitution is reflected in the Long R3 name. Analytical identity work therefore needs to distinguish LR3 from native IGF-1 and from the truncated DES(1-3) variant.

IGFBP interaction and signalling duration

IGFBPs regulate the distribution and availability of native IGF-1. LR3's modified sequence has reduced affinity for these binding proteins in experimental systems. Research models use that difference to compare short and extended signalling windows without treating the variants as interchangeable.

Receptor and pathway endpoints

LR3 binds the IGF-1 receptor, a receptor tyrosine kinase. Controlled models commonly measure receptor phosphorylation and downstream PI3K-AKT-mTOR and RAS-MAPK signals. Other endpoints include protein-synthesis markers, cell-cycle signals, cellular proliferation, and differentiation. These are laboratory measurements rather than claims about outcomes in people.

LR3 compared with native IGF-1 and DES

Native IGF-1 provides the parent 70-amino-acid sequence. LR3 extends that sequence and changes residue 3 to reduce IGFBP affinity. IGF-1 DES instead removes the first three N-terminal residues, creating a 67-amino-acid variant associated with short-window and localized signalling research. Separate names, specifications, and controls should be maintained for each material.

Analytical verification

Useful batch documentation identifies the stated compound, lot, physical form, and purity result. HPLC can characterize purity, while mass spectrometry can support molecular-identity assessment. Researchers should match any documentation to the batch identifier printed on the received vial rather than relying on a general product-family statement.

Research scope

This material is described solely for controlled laboratory research involving IGF-1R, IGFBP interactions, growth-signalling pathways, and cellular endpoints. Its scope is limited to laboratory receptor, binding-protein, pathway, and cellular-endpoint research.

References

• Ballard FJ et al. IGF variants and binding-protein interactions. Growth Factors literature.
• Bryant KJ et al. Design and characterization of Long R3 IGF-I muteins. Growth Factors. 1996.
• Xi G et al. IGFBP-3 effects on IGF-I and Long R3 IGF-I signalling in cell models. Journal of Cellular Physiology. 2004.

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