X-RAY STUDY OF HUMAN SERUM ALBUMIN COMPLEXED WITH HEME
[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.
Publication Abstract from PubMed
The high resolution structure of hemalbumin was determined by single crystal X-ray diffraction to a resolution of 1.9 A. The structure revealed the protoporphyrin IX bound to a single site within a hydrophobic cavity in subdomain IB, one of the principal binding sites for long chain fatty acid. The iron is penta coordinated with the fifth ligand comprised of the hydroxyl oxygen of Tyr-161 (phenolic oxygen to heme plane distance: 2.73 A) in an otherwise completely hydrophobic pocket. The heme propionic acid residues form salt bridges with His-142 and Lys-190, which together with a series of hydrophobic interactions, enclose and secure the heme within the IB helical motif. A detailed discussion of the structure together with its implications for the development of potential blood substitutes is presented.
The atomic structure of human methemalbumin at 1.9 A.,Wardell M, Wang Z, Ho JX, Robert J, Ruker F, Ruble J, Carter DC Biochem Biophys Res Commun. 2002 Mar 8;291(4):813-9. PMID:11866438
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.