IGF-1 LR3: Complete Research Guide & Chemical Profile

Long R3 Insulin-like Growth Factor-1 (IGF-1 LR3) is a synthetic analog of human IGF-1 that has been modified to enhance its stability and biological activity. This research peptide consists of 83 amino acids, compared to the 70 amino acids found in native IGF-1, making it a structurally distinct compound for laboratory investigations.

The molecular weight of IGF-1 LR3 is 9111.4 Da, and it features two key structural modifications: an arginine substitution at position 3 and a 13 amino acid N-terminal extension peptide. These modifications significantly alter the peptide's binding affinity to IGF binding proteins (IGFBPs), resulting in an extended half-life of 20-30 hours compared to native IGF-1's much shorter duration.

The complete amino acid sequence is: MFPAMPLSSL FVNGPRTLCG AELVDALQFV CGDRGFYFNK PTGYGSSSRR APQTGIVDEC CFRSCDLRRL EMYCAPLKPA KSA. This sequence represents the foundation for understanding the peptide's unique properties in research applications.

IGF-1 LR3 was originally developed to overcome the limitations of native IGF-1 in research settings. Studies have demonstrated that this analog maintains the biological activity of IGF-1 while providing enhanced stability and reduced binding to IGFBPs, making it a valuable tool for investigating growth factor pathways.

Research conducted by Francis and colleagues established the foundational understanding of IGF-1 LR3's modified binding properties. Their work demonstrated that the N-terminal extension and arginine substitution significantly reduce the peptide's affinity for IGFBPs, allowing for more direct interaction with IGF-1 receptors in laboratory models.

Cell culture studies have shown that IGF-1 LR3 exhibits enhanced potency compared to native IGF-1 in promoting cellular proliferation and protein synthesis. Research indicates that concentrations as low as 1-10 ng/mL can produce measurable effects in various cell lines, making it a potent research tool for studying growth factor signaling.

Animal model investigations have explored IGF-1 LR3's effects on muscle tissue, bone metabolism, and cellular regeneration processes. These studies have provided insights into the peptide's potential mechanisms and have contributed to our understanding of IGF-1 pathway modulation.

IGF-1 LR3 exerts its effects primarily through interaction with the IGF-1 receptor (IGF-1R), a tyrosine kinase receptor that plays a crucial role in cellular growth and metabolism regulation. Upon binding to IGF-1R, the peptide initiates a cascade of intracellular signaling pathways that influence various cellular processes.

The primary signaling pathways activated by IGF-1 LR3 include the PI3K/Akt pathway and the MAPK/ERK pathway. These pathways are fundamental to cellular proliferation, differentiation, and survival processes. Research suggests that the PI3K/Akt pathway is particularly important for the peptide's effects on protein synthesis and glucose metabolism.

Unlike native IGF-1, the structural modifications in IGF-1 LR3 result in reduced binding to IGFBPs, particularly IGFBP-3. This characteristic allows the peptide to remain bioactive for extended periods and interact more directly with target receptors. Laboratory studies indicate this property contributes to the peptide's enhanced potency and duration of action.

At the cellular level, IGF-1 LR3 has been observed to influence protein synthesis through mTOR pathway activation, promote glucose uptake in muscle cells, and modulate various aspects of cellular metabolism. These mechanisms make it a valuable research tool for investigating growth factor biology and metabolic processes.

IGF-1 LR3 is supplied as a lyophilized powder with a purity standard of ≥98% as determined by HPLC analysis. The peptide exhibits good solubility in sterile water and various buffer systems commonly used in laboratory research. Its chemical stability profile makes it suitable for a range of research applications when handled and stored properly.

The peptide contains multiple disulfide bonds that are critical for maintaining its three-dimensional structure and biological activity. These bonds contribute to the molecule's relative stability compared to linear peptides, though proper handling procedures remain essential for maintaining peptide integrity.

Lyophilized IGF-1 LR3 should be stored at -20°C or below to maintain stability. Under these conditions, the peptide typically remains stable for extended periods when protected from light and moisture. Research laboratories commonly store unopened vials in freezer conditions to preserve peptide integrity.

Once reconstituted, IGF-1 LR3 solutions should be stored at 4°C and used within a reasonable timeframe to ensure optimal activity. The addition of carrier proteins or specific buffer systems may enhance solution stability, though this should be validated for each specific research application.

High-quality IGF-1 LR3 for research applications should meet stringent purity standards. HPLC analysis typically confirms ≥98% purity, while mass spectrometry verification ensures correct molecular weight. Additional quality control measures may include amino acid analysis and bioactivity assays to verify peptide integrity and functionality.

Water content should be minimized in lyophilized preparations, typically maintained below 5% to prevent degradation. Bacterial endotoxin levels are also monitored in research-grade preparations to ensure suitability for cell culture and other sensitive applications.

Researchers seeking high-quality IGF-1 LR3 can find verified vendors and third-party tested batches on ChemVerify. Our platform provides comprehensive vendor verification, certificate of analysis review, and community feedback to help researchers identify reliable sources for their laboratory needs.

Visit our IGF-1 LR3 product page at /product/igf-1-lr3 to access current vendor listings, compare purity specifications, and review third-party testing data. ChemVerify's verification process ensures that listed suppliers meet strict quality standards and provide authentic research materials.

**What is the difference between IGF-1 and IGF-1 LR3 in research applications?**

IGF-1 LR3 differs from native IGF-1 through structural modifications that reduce IGFBP binding and extend its half-life. These changes result in enhanced potency and duration of action in laboratory studies, making it a preferred research tool for investigating IGF-1 pathways.

**How should IGF-1 LR3 be reconstituted for laboratory use?**

Research protocols typically involve reconstitution with sterile water or appropriate buffer systems. The specific reconstitution method should be validated for each research application, considering factors such as pH, ionic strength, and intended experimental conditions.

**What cell lines are commonly used in IGF-1 LR3 research?**

Various cell lines have been employed in IGF-1 LR3 research, including myoblast cultures, hepatocyte models, and adipocyte cell lines. The choice of cell line depends on the specific research objectives and the biological processes being investigated.

**What analytical methods are used to verify IGF-1 LR3 identity and purity?**

Standard analytical methods include HPLC for purity determination, mass spectrometry for molecular weight confirmation, and amino acid analysis for sequence verification. Some suppliers also provide bioactivity assays to confirm functional integrity.

**What are the typical concentration ranges used in cell culture studies?**

Published research indicates that IGF-1 LR3 concentrations ranging from 1-100 ng/mL are commonly employed in cell culture studies. The optimal concentration varies depending on the cell type, experimental objectives, and specific research protocols being followed.

**How does IGF-1 LR3 compare to other growth factors in research applications?**

IGF-1 LR3 offers unique advantages due to its extended half-life and reduced IGFBP binding compared to native IGF-1. When compared to other growth factors like PDGF or FGF, IGF-1 LR3 provides specific insights into IGF-1 receptor signaling pathways and related metabolic processes.

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