5l3l | pdb_00005l3l
D11 bound IGF-II
Structural highlights
Disease[IGF2_HUMAN] Epigenetic changes of DNA hypomethylation in IGF2 are a cause of Silver-Russell syndrome (SRS) [MIM:180860]. A clinically heterogeneous condition characterized by severe intrauterine growth retardation, poor postnatal growth, craniofacial features such as a triangular shaped face and a broad forehead, body asymmetry, and a variety of minor malformations. The phenotypic expression changes during childhood and adolescence, with the facial features and asymmetry usually becoming more subtle with age.[1] Function[IGF2_HUMAN] The insulin-like growth factors possess growth-promoting activity. In vitro, they are potent mitogens for cultured cells. IGF-II is influenced by placental lactogen and may play a role in fetal development.[2] Preptin undergoes glucose-mediated co-secretion with insulin, and acts as physiological amplifier of glucose-mediated insulin secretion. Exhibits osteogenic properties by increasing osteoblast mitogenic activity through phosphoactivation of MAPK1 and MAPK3.[3] Publication Abstract from PubMedInsulin and insulin-like growth factors I and II are closely related protein hormones. Their distinct evolution has resulted in different yet overlapping biological functions, with insulin becoming a key regulator of metabolism, while IGF-I/II are major growth factors. Insulin and IGFs cross-bind with different affinities to closely related insulin receptor isoforms A and B (IR-A and IR-B) and IGF-I receptor (IGF-1R). Identification of structural determinants in IGFs and insulin that trigger their specific signaling pathways is of increasing importance in designing receptor specific analogs with potential therapeutic applications. Here, we developed a straightforward protocol for production of recombinant IGF-II and prepared six IGF-II analogs with IGF-I-like mutations. All modified molecules exhibit significantly reduced affinity towards IR-A, particularly the analogs with Pro-Gln insertion in the C-domain. Moreover, one of the analogs has enhanced binding affinity for IGF-1R due to a synergistic effect of the Pro-Gln insertion and Ser29Asn point mutation. Consequently, this analog has almost a 10-fold higher IGF-1R/IR-A binding specificity in comparison with native IGF-II. The established IGF-II purification protocol allowed for a cost-effective isotope labeling required for a detailed NMR structural characterization of IGF-II analogs that revealed a link between the altered binding behavior of selected analogs and conformational rearrangement of their C-domain. Probing Receptor Specificity by Sampling the Conformational Space of the Insulin-like Growth Factor II C-domain.,Hexnerova R, Krizkova K, Fabry M, Sieglova I, Kedrova K, Collinsova M, Ullrichova P, Srb P, Williams C, Crump MP, Tosner Z, Jiracek J, Veverka V, Zakova L J Biol Chem. 2016 Aug 10. pii: jbc.M116.741041. PMID:27510031[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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