IGF-1 LR3

IGF-1 LR3

Clinical data
Routes of administration	Injection
Pharmacokinetic data
Biological half-life	20–30 hours
Identifiers
CAS Number	946870-92-4
ATC code	None
Synonyms	Long R3-IGF-1; IGF-1 Long R3
Chemical data
Formula	C400H625N111O115S9
Molecular 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.

See also

• des(1-3)IGF-1
• Mecasermin
• Mecasermin rinfabate
• Insulin-like growth factor 2