6qip
From Proteopedia
Ternary complex of FcRn ectodomain, FcRn binding optimised human serum albumin and the albumin-biniding side chain of the human growth hormone derivative somapacitan
Structural highlights
DiseaseALBU_HUMAN Defects in ALB are a cause of familial dysalbuminemic hyperthyroxinemia (FDH) [MIM:103600. FDH is a form of euthyroid hyperthyroxinemia that is due to increased affinity of ALB for T(4). It is the most common cause of inherited euthyroid hyperthyroxinemia in Caucasian population.[1] [2] [3] [4] FunctionALBU_HUMAN Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloidal osmotic pressure of blood. Major zinc transporter in plasma, typically binds about 80% of all plasma zinc.[5] Publication Abstract from PubMedSomapacitan, a human growth hormone derivative that binds reversibly to albumin, was investigated for human serum albumin (HSA) and HSA domain binding. Isothermal titration calorimetry (ITC) binding profiles showed high-affinity binding ( approximately 100-1000 nM) of one somapacitan molecule and low-affinity binding ( approximately 1000-10000 nM) of one to two somapacitan molecules to HSA. The high-affinity site was identified in HSA domain III using size exclusion chromatography (SEC) and ITC. SEC studies showed that the neonatal Fc receptor shields one binding site for somapacitan, indicating its position in domain III. A crystal structure of somapacitan in complex with HSA optimized for neonatal Fc receptor binding, having four amino acid residue replacements, identified a low-affinity site in fatty acid-binding site 6 (domain II). Surface plasmon resonance (SPR) showed these replacements affect the kinetics of the high-affinity binding site. Furthermore, small-angle X-ray scattering and SPR brace two somapacitan-binding sites on HSA. Identification of Binding Sites on Human Serum Albumin for Somapacitan, a Long-Acting Growth Hormone Derivative.,Johansson E, Nielsen AD, Demuth H, Wiberg C, Schjodt CB, Huang T, Chen J, Jensen S, Petersen J, Thygesen P Biochemistry. 2020 Apr 14;59(14):1410-1419. doi: 10.1021/acs.biochem.0c00019., Epub 2020 Mar 30. PMID:32208682[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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