1imx
1.8 Angstrom crystal structure of IGF-11.8 Angstrom crystal structure of IGF-1
Structural highlights
DiseaseIGF1_HUMAN Defects in IGF1 are the cause of insulin-like growth factor I deficiency (IGF1 deficiency) [MIM:608747. IGF1 deficiency is an autosomal recessive disorder characterized by growth retardation, sensorineural deafness and mental retardation. FunctionIGF1_HUMAN The insulin-like growth factors, isolated from plasma, are structurally and functionally related to insulin but have a much higher growth-promoting activity. May be a physiological regulator of [1-14C]-2-deoxy-D-glucose (2DG) transport and glycogen synthesis in osteoblasts. Stimulates glucose transport in rat bone-derived osteoblastic (PyMS) cells and is effective at much lower concentrations than insulin, not only regarding glycogen and DNA synthesis but also with regard to enhancing glucose uptake.[1] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDespite efforts spanning considerably more than a decade, a high-resolution view of the family of proteins known as insulin-like growth factors (IGFs) has remained elusive. IGF-1 consists of three helical segments which are connected by a 12-residue linker known as the C-region. NMR studies of members of this family reveal a dynamic structure with a topology resembling insulin but little structural definition in the C-region. We have crystallized IGF-1 in the presence of the detergent deoxy big CHAPS, and determined its structure at 1.8 A resolution by multiwavelength anomalous diffraction, exploiting the anomalous scattering of a single bromide ion and six of the seven sulfur atoms of IGF-1. The structure reveals a well-defined conformation for much of the C-region, which extends away from the core of IGF-1 and has residues known to be involved in receptor binding prominently displayed in a type II beta-turn. In the crystal, these residues form a dimer interface, but analytical ultracentrifugation experiments demonstrate that at physiological concentrations IGF-1 is monomeric. A single detergent molecule contacts residues known to be important for IGF-1 binding protein (IGFBP) interactions. Biophysical and biochemical data show that the detergent binds to IGF-1 specifically and blocks binding of IGFBP-1 and IGFBP-3. Crystal structure of human insulin-like growth factor-1: detergent binding inhibits binding protein interactions.,Vajdos FF, Ultsch M, Schaffer ML, Deshayes KD, Liu J, Skelton NJ, de Vos AM Biochemistry. 2001 Sep 18;40(37):11022-9. PMID:11551198[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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