3TCT

Structure of wild-type TTR in complex with tafamidis

Summary for 3TCT

• Entry DOI: 10.2210/pdb3tct/pdb
• Related: 2QGC 2QGD 2QGE
• Descriptor: Transthyretin, 2-(3,5-dichlorophenyl)-1,3-benzoxazole-6-carboxylic acid (3 entities in total)
• Functional Keywords: amyloid, amyloidosis, disease mutation, gamma-carboxyglutamic acid, glycoprotein, hormone, neuropathy, secreted, thyroid hormone, transport, kinetic stabilizer, inhibition of the amyloid cascade, binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Secreted: P02766
• Total number of polymer chains: 2
• Total formula weight: 28170.95

Authors

Connelly, S.,Kelly, J.W.,Wilson, I.A. (deposition date: 2011-08-09, release date: 2012-05-30, Last modification date: 2023-09-13)

Primary citation

Bulawa, C.E.,Connelly, S.,Devit, M.,Wang, L.,Weigel, C.,Fleming, J.A.,Packman, J.,Powers, E.T.,Wiseman, R.L.,Foss, T.R.,Wilson, I.A.,Kelly, J.W.,Labaudiniere, R.
Tafamidis, a potent and selective transthyretin kinetic stabilizer that inhibits the amyloid cascade.
Proc.Natl.Acad.Sci.USA, 109:9629-9634, 2012

PubMed Abstract: The transthyretin amyloidoses (ATTR) are invariably fatal diseases characterized by progressive neuropathy and/or cardiomyopathy. ATTR are caused by aggregation of transthyretin (TTR), a natively tetrameric protein involved in the transport of thyroxine and the vitamin A-retinol-binding protein complex. Mutations within TTR that cause autosomal dominant forms of disease facilitate tetramer dissociation, monomer misfolding, and aggregation, although wild-type TTR can also form amyloid fibrils in elderly patients. Because tetramer dissociation is the rate-limiting step in TTR amyloidogenesis, targeted therapies have focused on small molecules that kinetically stabilize the tetramer, inhibiting TTR amyloid fibril formation. One such compound, tafamidis meglumine (Fx-1006A), has recently completed Phase II/III trials for the treatment of Transthyretin Type Familial Amyloid Polyneuropathy (TTR-FAP) and demonstrated a slowing of disease progression in patients heterozygous for the V30M TTR mutation. Herein we describe the molecular and structural basis of TTR tetramer stabilization by tafamidis. Tafamidis binds selectively and with negative cooperativity (K(d)s ~2 nM and ~200 nM) to the two normally unoccupied thyroxine-binding sites of the tetramer, and kinetically stabilizes TTR. Patient-derived amyloidogenic variants of TTR, including kinetically and thermodynamically less stable mutants, are also stabilized by tafamidis binding. The crystal structure of tafamidis-bound TTR suggests that binding stabilizes the weaker dimer-dimer interface against dissociation, the rate-limiting step of amyloidogenesis.

PubMed: 22645360
DOI: 10.1073/pnas.1121005109

Experimental method

X-RAY DIFFRACTION (1.3 Å)