|Biological half-life||20–30 hours|
IGF-1 Long R3
|Chemical and physical data|
|Molar mass||9117.5 g/mol|
Long arginine 3-IGF-1, abbreviated as IGF-1 LR3 or as LR3-IGF-1, is a synthetic protein and lengthened analogue of human insulin-like growth factor 1 (IGF-1). It differs from native IGF-1 in that it possesses an arginine instead of a glutamic acid at the third position in its amino acid sequence ("arginine 3"), and also has an additional 13 amino acids at its N-terminus (MFPAMPLLSLFVN) ("long"), for a total of 83 amino acids (relative to the 70 of IGF-1). The consequences of these modifications are that IGF-1 LR3 retains the pharmacological activity of IGF-1 as an agonist of the IGF-1 receptor, has very low affinity for the insulin-like growth factor-binding proteins (IGFBPs), and has improved metabolic stability. As a result, it is approximately three times more potent than IGF-1, and possesses a significantly longer half-life of about 20–30 hours (relative to IGF-1's half-life of about 12–15 hours).
The amino acid sequence of IGF-1 LR3 is MFPAMPLSSL FVNGPRTLCG AELVDALQFV CGDRGFYFNK PTGYGSSSRR APQTGIVDEC CFRSCDLRRL EMYCAPLKPA KSA.
- Tomas FM, Lemmey AB, Read LC, Ballard FJ (1996). "Superior potency of infused IGF-I analogues which bind poorly to IGF-binding proteins is maintained when administered by injection". J. Endocrinol. 150 (1): 77–84. doi:10.1677/joe.0.1500077. PMID 8708565.
- Mohan S, Baylink DJ (2002). "IGF-binding proteins are multifunctional and act via IGF-dependent and -independent mechanisms". J. Endocrinol. 175 (1): 19–31. doi:10.1677/joe.0.1750019. PMID 12379487.
- Tomas FM, Knowles SE, Owens PC, Chandler CS, Francis GL, Read LC, Ballard FJ (1992). "Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats" (PDF). Biochem. J. 282 ( Pt 1): 91–7. PMC 1130894. PMID 1371669.
- von der Thüsen JH, Borensztajn KS, Moimas S, van Heiningen S, Teeling P, van Berkel TJ, Biessen EA (2011). "IGF-1 has plaque-stabilizing effects in atherosclerosis by altering vascular smooth muscle cell phenotype". Am. J. Pathol. 178 (2): 924–34. doi:10.1016/j.ajpath.2010.10.007. PMC 3069834. PMID 21281823.
- Mario Thevis (13 December 2010). Mass Spectrometry in Sports Drug Testing: Characterization of Prohibited Substances and Doping Control Analytical Assays. John Wiley & Sons. pp. 252–. ISBN 978-1-118-03514-6.