IGF1 LR3 (insulin-like growth factor-1 Long R3) is a non-glycosylated, recombinant polypeptide chain made up of 83 amino acids. IGF1 LR3 is the recombinant form of human IGF-1, and as such it contains the entire native amino acid sequence but with two major modifications: substitution of arginine (abbreviated R or arg) at position 3 with glutamic acid (abbreviated E or Glu) hence the label R3; and the extension of the N-terminus of the native sequence by a 13 amino-acid peptide hence the label long.
The native form of a polypeptide refers to the naturally occurring amino acid sequence and the resultant conformational structure. The molecular weight of IGF1 LR3 as measured by Mass Spectrometry is 9.116 kD (kiloDaltons). A specifically designed protein expression system is utilized in the production of IGF1 LR3 in Escherichia Coli. Thereafter, chromatographic techniques are used to correctly fold and purify the IGF1 LR3 to the highly-active and functional IGF1 LR3 that can bind to human IGF-1R (insulin-like growth factor-1 receptor).
April 14, 2026