1qwh

From Proteopedia

a covalent dimer of transthyretin that affects the amyloid pathway

Overview

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.

Disease

Known diseases associated with this structure: Amyloid neuropathy, familial, several allelic types OMIM:[176300], Amyloidosis, senile systemic OMIM:[176300], Carpal tunnel syndrome, familial OMIM:[176300], Dystransthyretinemic hyperthyroxinemia OMIM:[176300]

About this Structure

1QWH is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Kinetic stabilization of the native state by protein engineering: implications for inhibition of transthyretin amyloidogenesis., Foss TR, Kelker MS, Wiseman RL, Wilson IA, Kelly JW, J Mol Biol. 2005 Apr 8;347(4):841-54. PMID:15769474

Page seeded by OCA on Mon Nov 12 18:57:05 2007