Metabolic Effects of IGFs

摘要: The relationship between insulin-like growth factors (IGFs) and insulin has been known since the discovery of nonsuppressible activity (NSILA) in serum at beginning 1960s (1), was derived from similarities their biological actions. In mid-1970s it found that NSILA consisted two polypeptides termed IGF-I IGF-II. They turned out to be not only biologically but also structurally closely related (2,3). This finding first surprising, because had based on a most prominent feature essentially distinguished insulin: its complete lack cross-reactivity with antibodies. However, after elucidation primary tertiary structures -II (2–4),the reason for this became apparent (Fig. 1). Insulin contains main antibody binding sites. One them comprises amino (N)-terminal region B chain (B2, B3, B4) plus an adjacent A (A8, A9, A10). is completely different IGFs. second site residues Al A19–A21 carboxyl (C)-terminal chain, covered IGFs by C domain C-terminal extension called D domain.