[ALBU_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.
[ALBU_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.
The primary ligands of human serum albumin (HSA), an abundant plasma protein, are non-esterified fatty acids. In vivo, the majority of fatty acids associated with the protein are unsaturated. We present here the first high-resolution crystal structures of HSA complexed with two important unsaturated fatty acids, the monounsaturated oleic acid (C18:1) and the polyunsaturated arachidonic acid (C20:4). Both compounds are observed to occupy the seven binding sites distributed across the protein that are also bound by medium and long-chain saturated fatty acids. Although C18:1 fatty acid binds each site on HSA in a conformation almost identical with that of the corresponding saturated compound (C18:0), the presence of multiple cis double bonds in C20:4 induces distinct binding configurations at some sites. The observed restriction on binding configurations plausibly accounts for differences in the pattern of binding affinities for the primary sites between polyunsaturated fatty acids and their saturated or monounsaturated counterparts.
Crystal structures of human serum albumin complexed with monounsaturated and polyunsaturated fatty acids.,Petitpas I, Grune T, Bhattacharya AA, Curry S J Mol Biol. 2001 Dec 14;314(5):955-60. PMID:11743713
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
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↑ Wada N, Chiba H, Shimizu C, Kijima H, Kubo M, Koike T. A novel missense mutation in codon 218 of the albumin gene in a distinct phenotype of familial dysalbuminemic hyperthyroxinemia in a Japanese kindred. J Clin Endocrinol Metab. 1997 Oct;82(10):3246-50. PMID:9329347
↑ Lu J, Stewart AJ, Sadler PJ, Pinheiro TJ, Blindauer CA. Albumin as a zinc carrier: properties of its high-affinity zinc-binding site. Biochem Soc Trans. 2008 Dec;36(Pt 6):1317-21. doi: 10.1042/BST0361317. PMID:19021548 doi:10.1042/BST0361317
↑ Petitpas I, Grune T, Bhattacharya AA, Curry S. Crystal structures of human serum albumin complexed with monounsaturated and polyunsaturated fatty acids. J Mol Biol. 2001 Dec 14;314(5):955-60. PMID:11743713 doi:http://dx.doi.org/10.1006/jmbi.2000.5208