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Growth Factors

IGF-1 LR3

Long R3 IGF-1 / LR3-IGF-1

IGF-1 LR3 is a recombinant of insulin-like growth factor 1 with an N-terminal extension and an arginine substitution at position 3. The modifications reduce binding to IGFBPs (IGF binding proteins) and prolong activity, making LR3 IGF-1 a common reagent in cell-culture and animal-physiology research. It is not approved for human use.

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Growth Factors
Classification
Recombinant long Arg3 analogue of insulin-like growth factor 1
Research stage
Research and biomanufacturing literature; veterinary in vivo studies; no human therapeutic approval
Sequence
Native IGF-1 with N-terminal MFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPT extension and Arg3 substitution
Molecular weight
9111 Da (approx.)

Snapshot

Key takeaways

A three-bullet snapshot before reading the full dossier.

  1. 01

    Recombinant IGF-1 variant designed to evade IGFBP binding and prolong activity.

  2. 02

    Common cell-culture and bioproduction reagent; veterinary and developmental-physiology research literature exists.

  3. 03

    Not approved for human therapeutic use.

Dossier overview

4

research areas

3

references

3

handling notes

01

Mechanism of action

IGF-1 LR3 activates the IGF-1 with similar affinity to native IGF-1 but reduced binding to circulating IGFBPs, increasing its in research models. involves PI3K/Akt and pathways implicated in cellular growth and survival.

02

Research applications

  • Cell-culture supplement and bioreactor research
  • Animal-physiology and developmental research
  • IGF-axis pharmacology
  • Recombinant protein expression methodology

Evidence at a glance

What's behind this profile

3 citations · 1999–2023

Other
3

Studies that did not match the categories above.

Publication years

  1. 99
  2. 00
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  25. 23
19992023

Counts are derived from the cited studies below. A study covering both in vivo and in vitro work is counted by its primary model. Sample size is reported in 1 of 3 citations. Findings remain model-specific and are not extrapolated to therapeutic use.

03

Study references

Each profile cites a minimum of two peer-reviewed sources, with model type and reported sample size where the source provides it. Findings are model-specific and must not be extrapolated to therapeutic use.

Recombinant expression of IGF-1 and LR3 IGF-1 fused with xylanase in Pichia pastoris

2023

Lu Z et al. · Applied Microbiology and Biotechnology

Model
Recombinant protein expression in Pichia pastoris (15-L bioreactor)
Sample
N/A (bioprocess methodology)

Reported successful high-level expression of IGF-1 and LR3 IGF-1 as xylanase-fusion proteins in P. pastoris with retained bioactivity.

PMID 37261455 DOI 10.1007/s00253-023-12606-0

Action of long(R3)-insulin-like growth factor-1 on protein metabolism in beef heifers

1999

Hill RA et al. · Domestic Animal Endocrinology

Model
In vivo — intravenous infusion in undernourished beef heifers
Sample
Not reported in abstract

Long(R3)-IGF-1 infusion in undernourished heifers was associated with a tendency for whole-body and skeletal muscle protein to be conserved.

PMID 10370861 DOI 10.1016/s0739-7240(99)00015-6

Coronary vascular growth matches IGF-1-stimulated cardiac growth in fetal sheep

2020

Jonker SS et al. · FASEB Journal

Model
In vivo — near-term fetal sheep with surgical instrumentation
Sample
Fetal sheep at 127–134 days gestation (n not specified in abstract)

IGF-1 LR3 treatment in fetal sheep was associated with increased cardiomyocyte proliferation alongside matched coronary vascular expansion.

PMID 32573852 DOI 10.1096/fj.202000215R

Evidence caveats

  • IGF-1 LR3 is not approved for human therapeutic use in any jurisdiction. The published literature is dominated by cell-culture, biomanufacturing, and animal-physiology research.
  • Like other IGF-axis agents, LR3 IGF-1 is on the World Anti-Doping Agency prohibited list.

04

Storage and handling

Store under controlled laboratory conditions with batch and preparation details recorded.

  • Maintain cold-chain and batch traceability for cell-culture and research reagent use.
  • Avoid repeated cycles for stock solutions.
  • Research-only inventory; not for human use.

Common questions

IGF-1 LR3 FAQ

Plain-English answers backed by the citations on this profile — what it is, what's been studied, regulatory status, evidence limits.

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