L-thyroxine(T4)

The crystal structure of human transthyretin (TTR) complexed with milrinone (2-methyl-5-cyano-3,4"-bipyridin-6(1H)-one), a positive inotropic cardiac agent, has been refined to R = 17.4% for 8-1.9-A resolution data. This report provides the first detailed description of protein interactions for an inotropic bipyridine agent which is an effective thyroid hormone binding competitor to transthyretin....

The first observation of a unique tetrameric molecular structure of transthyretin from rat (rTTR, prealbumin) is reported. The structure has been determined by X-ray diffraction using molecular replacement and the structure of human transthyretin (hTTR) as a starting model. Crystals of native rat transthyretin are tetragonal, space group P4(3)2(1)2, and have four independent monomers in the asymmetric unit of the crystal lattice....

Human serum albumin (HSA) is the major protein component of blood plasma and serves as a transporter for thyroxine and other hydrophobic compounds such as fatty acids and bilirubin. We report here a structural characterization of HSA-thyroxine interactions. Using crystallographic analyses we have identified four binding sites for thyroxine on HSA distributed in subdomains IIA, IIIA, and IIIB....

Transthyretin (TTR) is an extracellular transport protein involved in the distribution of thyroid hormones and vitamin A. So far, TTR has only been found in vertebrates, of which piscine TTR displays the lowest sequence identity with human TTR (47%). Human and piscine TTR bind both thyroid hormones 3,5,3"-triiodo-l-thyronine (T(3)) and 3,5,3",5"-tetraiodo-l-thyronine (thyroxine, T(4))....

Thyroid hormone (TH) actions are mediated by nuclear receptors (TRs alpha and beta) that bind triiodothyronine (T(3), 3,5,3"-triiodo-l-thyronine) with high affinity, and its precursor thyroxine (T(4), 3,5,3",5"-tetraiodo-l-thyronine) with lower affinity. T(4) contains a bulky 5" iodine group absent from T(3). Because T(3) is buried in the core of the ligand binding domain (LBD), we have predicted that TH analogues with 5" substituents should fit poorly into the ligand binding pocket and perhaps behave as antagonists....

The hormones that most directly control tissue activities in health and disease are delivered by two noninhibitory members of the serpin family of protease inhibitors, thyroxine-binding globulin (TBG) and corticosteroid-binding globulin. The structure of TBG bound to tetra-iodo thyroxine, solved here at 2.8 A, shows how the thyroxine is carried in a surface pocket on the molecule....

The crystal structure of human transthyretin (TTR) complexed with milrinone (2-methyl-5-cyano-3,4"-bipyridin-6(1H)-one), a positive inotropic cardiac agent, has been refined to R = 17.4% for 8-1.9-A resolution data. This report provides the first detailed description of protein interactions for an inotropic bipyridine agent which is an effective thyroid hormone binding competitor to transthyretin....

Deposition: Zhou A, Wei Z, Stanley PLD, Read RJ, Stein PE, Carrell RW, 2007/10/12

The x-ray crystal structures of normal human transthyretin (prealbumin) and the amyloidogenic Val-30-Met variant have been refined at 1.7-A resolution to R-values of 0.168 and 0.179, respectively, for 19,882 and 20,362 reflections (Fobs > 2.0 sigma). Standard deviations for stereochemical parameters are 0.018 and 0.022 A for bond distances, 0.030 and 0.038 A for angle distances, and 0.035 and 0.070 A for planar 1-4 distances....

The x-ray crystal structures of normal human transthyretin (prealbumin) and the amyloidogenic Val-30-Met variant have been refined at 1.7-A resolution to R-values of 0.168 and 0.179, respectively, for 19,882 and 20,362 reflections (Fobs > 2.0 sigma). Standard deviations for stereochemical parameters are 0.018 and 0.022 A for bond distances, 0.030 and 0.038 A for angle distances, and 0.035 and 0.070 A for planar 1-4 distances....

GASTROINTESTINAL: NAUSEA OR VOMITING