2b9a | pdb_00002b9a

Human transthyretin (TTR) complexed with diflunisal analogues- TTR.3',5'-difluorobiphenyl-4-carboxylic acid

spinqualitylabelsall models 2b9a, resolution 1.54Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2b9a is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FBC Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Disease [TTHY_HUMAN] Defects in TTR are the cause of amyloidosis transthyretin-related (AMYL-TTR) [MIM:105210]. A hereditary generalized amyloidosis due to transthyretin amyloid deposition. Protein fibrils can form in different tissues leading to amyloid polyneuropathies, amyloidotic cardiomyopathy, carpal tunnel syndrome, systemic senile amyloidosis. The disease includes leptomeningeal amyloidosis that is characterized by primary involvement of the central nervous system. Neuropathologic examination shows amyloid in the walls of leptomeningeal vessels, in pia arachnoid, and subpial deposits. Some patients also develop vitreous amyloid deposition that leads to visual impairment (oculoleptomeningeal amyloidosis). Clinical features include seizures, stroke-like episodes, dementia, psychomotor deterioration, variable amyloid deposition in the vitreous humor. Defects in TTR are a cause of hyperthyroxinemia dystransthyretinemic euthyroidal (HTDE) [MIM:145680]. It is a condition characterized by elevation of total and free thyroxine in healthy, euthyroid persons without detectable binding protein abnormalities. Defects in TTR are a cause of carpal tunnel syndrome type 1 (CTS1) [MIM:115430]. It is a condition characterized by entrapment of the median nerve within the carpal tunnel. Symptoms include burning pain and paresthesias involving the ventral surface of the hand and fingers which may radiate proximally. Impairment of sensation in the distribution of the median nerve and thenar muscle atrophy may occur. This condition may be associated with repetitive occupational trauma, wrist injuries, amyloid neuropathies, rheumatoid arthritis. Function [TTHY_HUMAN] Thyroid hormone-binding protein. Probably transports thyroxine from the bloodstream to the brain. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Analogues of diflunisal, an FDA-approved nonsteroidal antiinflammatory drug (NSAID), were synthesized and evaluated as inhibitors of transthyretin (TTR) aggregation, including amyloid fibril formation. High inhibitory activity was observed for 26 of the compounds. Of those, eight exhibited excellent binding selectivity for TTR in human plasma (binding stoichiometry >0.50, with a theoretical maximum of 2.0 inhibitors bound per TTR tetramer). Biophysical studies reveal that these eight inhibitors dramatically slow tetramer dissociation (the rate-determining step of amyloidogenesis) over a duration of 168 h. This appears to be achieved through ground-state stabilization, which raises the kinetic barrier for tetramer dissociation. Kinetic stabilization of WT TTR by these eight inhibitors is further substantiated by the decreasing rate of amyloid fibril formation as a function of increasing inhibitor concentration (pH 4.4). X-ray cocrystal structures of the TTR.18(2) and TTR.20(2) complexes reveal that 18 and 20 bind in opposite orientations in the TTR binding site. Moving the fluorines from the meta positions in 18 to the ortho positions in 20 reverses the binding orientation, allowing the hydrophilic aromatic ring of 20 to orient in the outer binding pocket where the carboxylate engages in favorable electrostatic interactions with the epsilon-ammonium groups of Lys 15 and 15'. The hydrophilic aryl ring of 18 occupies the inner binding pocket, with the carboxylate positioned to hydrogen bond to the serine 117 and 117' residues. Diflunisal itself appears to occupy both orientations based on the electron density in the TTR.1(2) structure. Structure-activity relationships reveal that para-carboxylate substitution on the hydrophilic ring and dihalogen substitution on the hydrophobic ring afford the most active TTR amyloid inhibitors. Diflunisal analogues stabilize the native state of transthyretin. Potent inhibition of amyloidogenesis.,Adamski-Werner SL, Palaninathan SK, Sacchettini JC, Kelly JW J Med Chem. 2004 Jan 15;47(2):355-74. PMID:14711308 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Transthyretin

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