Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2010 Aug 27;285(35):27302-13. doi: 10.1074/jbc.M110.145318. Epub 2010 Jun 21.

Human Tau isoforms assemble into ribbon-like fibrils that display polymorphic structure and stability.

Author information

  • 1Department of Biosystems Science and Engineering, ETH Zürich, CH-4058 Basel, Switzerland.

Abstract

Fibrous aggregates of Tau protein are characteristic features of Alzheimer disease. We applied high resolution atomic force and EM microscopy to study fibrils assembled from different human Tau isoforms and domains. All fibrils reveal structural polymorphism; the "thin twisted" and "thin smooth" fibrils resemble flat ribbons (cross-section approximately 10 x 15 nm) with diverse twist periodicities. "Thick fibrils" show periodicities of approximately 65-70 nm and thicknesses of approximately 9-18 nm such as routinely reported for "paired helical filaments" but structurally resemble heavily twisted ribbons. Therefore, thin and thick fibrils assembled from different human Tau isoforms challenge current structural models of paired helical filaments. Furthermore, all Tau fibrils reveal axial subperiodicities of approximately 17-19 nm and, upon exposure to mechanical stress or hydrophobic surfaces, disassemble into uniform fragments that remain connected by thin thread-like structures ( approximately 2 nm). This hydrophobically induced disassembly is inhibited at enhanced electrolyte concentrations, indicating that the fragments resemble structural building blocks and the fibril integrity depends largely on hydrophobic and electrostatic interactions. Because full-length Tau and repeat domain constructs assemble into fibrils of similar thickness, the "fuzzy coat" of Tau protein termini surrounding the fibril axis is nearly invisible for atomic force microscopy and EM, presumably because of its high flexibility.

PMID:
20566652
[PubMed - indexed for MEDLINE]
PMCID:
PMC2930729
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk