Protein
des(1-3)IGF-1 is a naturally occurring , endogenous protein , as well as drug , and truncated analogue of insulin-like growth factor 1 (IGF-1).[ 1] [ 2] [ 3] [ 4] des(1-3)IGF-1 lacks the first three amino acids at the N-terminus of IGF-1 (for a total of 67 amino acids, relative to the 70 of IGF-1).[ 5] As a result of this difference, it has considerably reduced binding to the insulin-like growth factor-binding proteins (IGFBPs) and enhanced potency (about 10-fold in vivo ) relative to IGF-1.[ 1] [ 2] [ 3] [ 5]
The amino acid sequence of des(1-3)IGF-1 is TLCGAELVDA LQFVCGDRGF YFNKPTGYGS SSRRAPQTGI VDECCFRSCD LRRLEMYCAP LKPAKSA.[ 5]
^ a b Gillespie C, Read LC, Bagley CJ, Ballard FJ (1990). "Enhanced potency of truncated insulin-like growth factor-I (des(1-3)IGF-I) relative to IGF-I in lit/lit mice" . J. Endocrinol . 127 (3): 401–5. doi :10.1677/joe.0.1270401 . PMID 2280209 .
^ a b Simes JM, Wallace JC, Walton PE (1991). "The effects of insulin-like growth factor-I (IGF-I), IGF-II and des(1-3)IGF-I, a potent IGF analogue, on growth hormone and IGF-binding protein secretion from cultured rat anterior pituitary cells" . J. Endocrinol . 130 (1): 93–9. doi :10.1677/joe.0.1300093 . PMID 1715381 .
^ a b Ballard FJ, Wallace JC, Francis GL, Read LC, Tomas FM (1996). "Des(1-3)IGF-I: a truncated form of insulin-like growth factor-I". Int. J. Biochem. Cell Biol . 28 (10): 1085–7. doi :10.1016/1357-2725(96)00056-8 . PMID 8930132 .
^ Yamamoto H, Murphy LJ (1995). "Enzymatic conversion of IGF-I to des(1-3)IGF-I in rat serum and tissues: a further potential site of growth hormone regulation of IGF-I action" . J. Endocrinol . 146 (1): 141–8. doi :10.1677/joe.0.1460141 . PMID 7561610 .
^ a b c 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 .