Long[R3] insulin-like growth factor-I (IGF-1 Long[R3] ) is a Human Recombinant, single, non-glycosylated, polypeptide chain containing 83 amino acids. It is an analog of human IGF-1 comprising the complete human IGF-1 sequence with the substitution of an Arginine (Arg or R) for the Glutamic Acid (Glu or E) at position 3 (hence R3), and a 13 amino acid extension peptide at the N-terminus.
This analog has been engineered with the express purpose of increasing biological activity. IGF-1 Long[R3] is significantly more potent than IGF-1 in vitro and in vivo. The enhanced potency is due to the markedly decreased binding of IGF-1 Long[R3] to all IGF binding proteins. These binding proteins normally inhibit the biological actions of IGFs.
IGF-1 stands for insulin-like growth factor. It is a natural substance that is produced in the human body and is at its highest natural levels during puberty. During puberty IGF-1 is the most responsible for the natural muscle growth that occurs during these few years. There are many different things that IGF-1 does in the human body.
Among the effects the most positive are:
. increased amino acid transport to cells
. increased glucose transport
. increased protein synthesis
. decreased protein degradation
. increased RNA synthesis.