1QWH

a covalent dimer of transthyretin that affects the amyloid pathway

Summary for 1QWH

• Entry DOI: 10.2210/pdb1qwh/pdb
• Descriptor: Transthyretin (2 entities in total)
• Functional Keywords: thyroid hormone, liver, plasma, cerebrospinal fluid, polyneuropathy, disease mutation, transport, thyroxine, binding protein, hormone-growth factor complex, hormone/growth factor
• Biological source: Homo sapiens (human)
• Cellular location: Secreted: P02766
• Total number of polymer chains: 2
• Total formula weight: 25716.74

Authors

Foss, T.,Kelker, M.S.,Wilson, I.A. (deposition date: 2003-09-02, release date: 2004-09-14, Last modification date: 2023-08-16)

Primary citation

Foss, T.R.,Kelker, M.S.,Wiseman, R.L.,Wilson, I.A.,Kelly, J.W.
Kinetic stabilization of the native state by protein engineering: implications for inhibition of transthyretin amyloidogenesis.
J.Mol.Biol., 347:841-854, 2005

PubMed Abstract: The amyloidogenic homotetrameric protein transthyretin (TTR) must undergo rate-limiting dissociation to partially denatured monomers in order to aggregate. TTR contains two distinct quaternary interfaces, one of which defines the binding sites for thyroxine and small-molecule amyloidogenesis inhibitors. Kinetic stabilization of the tetramer can be accomplished either by the binding of amyloidogenesis inhibitors selectively to the native state over the dissociative transition state or by the introduction of trans-suppressor subunits (T119M) into heterotetramers to destabilize the dissociative transition state. In each case, increasing the dissociation activation barrier prevents tetramer dissociation. Herein, we demonstrate that tethering two subunits whose quaternary interface defines the thyroxine binding site also dramatically increases the barrier for tetramer dissociation, apparently by destabilization of the dissociative transition state. The tethered construct (TTR-L-TTR)2 is structurally and functionally equivalent to wild-type TTR. Urea is unable to denature (TTR-L-TTR)2, yet it is able to maintain the denatured state once denaturation is achieved by GdnHCl treatment, suggesting that (TTR-L-TTR)2 is kinetically rather than thermodynamically stabilized, consistent with the identical wild-type TTR and (TTR-L-TTR)2 GdnHCl denaturation curves. Studies focused on a construct containing a single TTR-L-TTR chain and two normal monomer subunits establish that alteration of only one quaternary structural interface is sufficient to impose kinetic stabilization on the entire quaternary structure.

PubMed: 15769474
DOI: 10.1016/j.jmb.2005.01.050

Experimental method

X-RAY DIFFRACTION (1.36 Å)