Long arginine 3-IGF-1, abbreviated as IGF-1 LR3 or LR3-IGF-1, is a synthetic

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

and lengthened analogue of

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

insulin-like growth factor 1 Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a hormone similar in molecular structure to insulin which plays an important role in childhood growth, and has anabolic effects in adults. IGF-1 is a protein that in humans ...

(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 Protein primary structure is the linear sequence of amino acids in a peptide or protein. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end. Protein biosynthe ...

("arginine 3"), and also has an additional 13

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha a ...

s 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 In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

of IGF-1 as an agonist of the

IGF-1 receptor The insulin-like growth factor 1 (IGF-1) receptor is a protein found on the surface of human cells. It is a transmembrane receptor that is activated by a hormone called insulin-like growth factor 1 ( IGF-1) and by a related hormone called IGF-2. ...

, has very low

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Par ...

for the

insulin-like growth factor-binding protein The insulin-like growth factor-binding protein (IGFBP) serves as a transport protein for insulin-like growth factor 1 (IGF-1). Function Approximately 98% of IGF-1 is always bound to one of six binding proteins (IGF-BP). IGFBP-3, the most abund ...

s (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 Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

of about 20–30 hours (relative to IGF-1's half-life of about 12–15 hours). The

of IGF-1 LR3 is MFPAMPLSSL FVNGPRTLCG AELVDALQFV CGDRGFYFNK PTGYGSSSRR APQTGIVDEC CFRSCDLRRL EMYCAPLKPA KSA.

References

Growth hormones Insulin-like growth factor receptor agonists Recombinant proteins {{systemic-hormonal-drug-stub

See also

References