Transthyretin (TTR) is a carrier protein that is involved in the binding and transport of thyroid hormone and the retinol binding protein/vitamin A complex. TTR is normally present in human plasma and cerobrospinal fluid as a soluble, tetrameric protein, but in several disease conditions can be converted into insoluble amyloid. More than 80 point mutations in TTR have been described and implicated in a group of diseases known collectively as familial amyloid polyneuropathy (FAP). Previous studies have shown that dissociation of the tetramer is rate-limiting for fibril formation in vitro; furthermore, the severity of FAP disease is correlated with the thermodynamic and kinetic stability of the variant tetramers. This study will focus on the mechanism of fibril formation by wild-type and variant TTR using engineered monomeric forms of TTR. The kinetics of the reaction will be examined, and intermediates in the pathway from amyloidogenic monomers to mature fibrils will be characterized using turbidity and dye-binding assays, electron microscopy, analytical ultracentrifugation, and time-lapse atomic force microscopy. These studies will address whether fibrillization is a nucleation dependent polymerization that can be seeded in vivo and whether FAP-variants differ from wild-type TTR in the fibril formation pathway. The results will enhance our understanding of TTR amyloid disease and may shed light on the nature of the intermediates responsible for cellular toxicity. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM067348-02
Application #
6706315
Study Section
Special Emphasis Panel (ZRG1-F04 (20))
Program Officer
Lograsso, Philip
Project Start
2003-03-19
Project End
2005-03-18
Budget Start
2004-03-19
Budget End
2005-03-18
Support Year
2
Fiscal Year
2004
Total Cost
$50,548
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
781613492
City
La Jolla
State
CA
Country
United States
Zip Code
92037