IGF-1 LR3

IGF-1 LR3 — Long-Acting Recombinant IGF-1 Research Protein

IGF-1 LR3 (Long-Arg3 Insulin-like Growth Factor 1) is a recombinant analog of human Insulin-like Growth Factor 1 (IGF-1) produced through bacterial expression systems and modified at two structural positions to alter its pharmacokinetic and binding profile relative to native IGF-1. The 13-amino-acid N-terminal extension increases the protein’s stability and significantly extends its half-life, while the Arg-3 substitution (replacing glutamate-3 with arginine) reduces binding affinity for IGF binding proteins (IGFBPs), increasing free bioactive availability in research applications. These modifications have made IGF-1 LR3 one of the most extensively used research proteins in cell culture and IGF-pathway research literature.

Mechanism of Action

IGF-1 LR3 has been investigated in published research for activity across several biological pathways, including:

• IGF-1 receptor (IGF-1R) agonism — binding to the IGF-1 receptor, a receptor tyrosine kinase widely expressed across tissue types
• Reduced IGFBP binding — the Arg-3 substitution significantly reduces affinity for IGF binding proteins, allowing IGF-1 LR3 to remain bioactive in IGFBP-containing research environments where native IGF-1 would be sequestered
• PI3K/Akt pathway activation — downstream signaling cascade research, including investigations into Akt phosphorylation and mTOR pathway activity
• MAPK/ERK pathway research — investigations into mitogen-activated protein kinase signaling downstream of IGF-1R activation
• Insulin receptor cross-reactivity — research on IGF-1 LR3’s documented cross-reactivity with insulin receptor signaling pathways at higher concentrations
• Cellular proliferation research — extensive use in cell culture applications as a growth factor supplement for studying cellular proliferation pathways
• Comparative IGF research — comparative studies against native IGF-1, IGF-2, and other IGF-1 analogs

IGF-1 LR3 is distinguished in research literature by two characteristics: its extended bioactive half-life relative to native IGF-1 (approximately 20-30 hours versus 10-12 minutes for unmodified IGF-1), and its reduced IGFBP binding which makes it the preferred IGF-1 analog for cell culture research where IGFBP interference is a methodological concern.

Research Applications

IGF-1 LR3 is widely used in research contexts including:

• Cell culture research as a growth factor supplement for cellular proliferation studies
• IGF-1 receptor pharmacology and signaling pathway research
• PI3K/Akt and MAPK/ERK pathway research
• Comparative IGF analog research alongside native IGF-1 and IGF-2
• Stem cell and progenitor cell research models
• Skeletal muscle, cardiac, and hepatic cell research models
• Cellular metabolism and protein synthesis research
• Aging and cellular senescence research models

Product Specifications

• Compound: IGF-1 LR3 (Long-Arg3 Insulin-like Growth Factor 1)
• Source: Recombinant, expressed in E. coli bacterial expression system
• Form: Lyophilized powder
• Purity: ≥98% (verified by HPLC, SDS-PAGE, and mass spectrometry)
• Bioactivity: Verified by ELISA / cell-based bioassay
• Available sizes: 1mg
• Third-party tested: Certificate of Analysis with bioactivity confirmation available on request

Reconstitution & Storage

Lyophilized IGF-1 LR3 should be stored at -20°C for long-term stability and protected from light. As a recombinant protein, IGF-1 LR3 is particularly sensitive to repeated freeze-thaw cycles and elevated temperatures — protein denaturation and loss of bioactivity can occur with improper handling. Once reconstituted with bacteriostatic water or acidified sterile water (some research protocols use 10mM acetic acid as a reconstitution buffer to enhance solubility), the solution should be aliquoted and stored at -20°C for long-term storage, or refrigerated at 2–8°C for short-term use within the timeframe indicated on the product COA.

Researchers should consult published literature for reconstitution buffer recommendations specific to their research model and downstream application.

Shipping & Handling

All orders are shipped with temperature-controlled packaging to preserve protein integrity. Orders ship within the United States only. Domestic orders typically arrive within 2–4 business days. Tracking is provided on every order.

Important Disclaimer

This product is sold strictly for laboratory research and in-vitro use only, including use as a growth factor supplement in cell culture applications. It is not intended for human or animal consumption, diagnostic use, therapeutic use, athletic performance enhancement, bodybuilding, or any form of clinical, medical, or personal application. By purchasing, you confirm that you are a qualified researcher or affiliated with a licensed research institution and that this product will be handled in accordance with all applicable laws and safety standards.

IGF-1 LR3 is not approved by the FDA for human use, and this product is not a substitute for any prescribed medication. IGF-1 LR3 is included on the World Anti-Doping Agency (WADA) prohibited substances list. Use outside of qualified laboratory research is not permitted under the terms of sale.