Human IGF-I Protein, Fc Tag (MALS verified)

Insulin-like growth factor 1 (IGF-1 or IGF-I), also known as somatomedin C, is the dominant effector of growth hormone and is structurally homologous to proinsulin. Human IGF-1 is synthesized as two precursor isoforms with N- and alternate C‑terminal propeptides (1) . These isoforms are differentially expressed by various tissues (1) . The 7.6 kDa mature IGF‑1 is identical between isoforms and is generated by proteolytic removal of the N- and C‑terminal regions. Mature human IGF-1 shares 94% and 96% aa sequence identity with mouse and rat IGF-1, respectively (2), and exhibits cross-species activity. It shares 64% aa sequence identity with mature human IGF2. Circulating IGF-1 is produced by hepatocytes, while local IGF-1 is produced by many other tissues in which it has paracrine effects (1) . IGF-1 induces the proliferation, migration, and differentiation of a wide variety of cell types during development and postnatally (3) . IGF-1 regulates glucose and fatty acid metabolism, steroid hormone activity, and cartilage and bone metabolism (4‑7) . It plays an important role in muscle regeneration and tumor progression (1, 8) . IGF-1 binds IGF1R, IGF2R, and the insulin receptor, although its effects are mediated primarily by IGF1R (9) . IGF-1 association with IGF binding proteins increases its plasma half‑life and modulates its interactions with receptors (10) .