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Related Experiment Video

Updated: May 24, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Published on: March 21, 2025

An equilibrium model for linear and closed-loop amyloid fibril formation.

Shuo Yang¹, Michael D W Griffin, Katrina J Binger

¹Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia.

Journal of Molecular Biology

|February 29, 2012

Summary

Human apolipoprotein C-II forms reversible amyloid fibrils through a self-assembly process. A new model explains fibril size distribution and closed-loop formation, offering insights into age-related disease mechanisms.

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Analysis of β-Amyloid-induced Abnormalities on Fibrin Clot Structure by Spectroscopy and Scanning Electron Microscopy

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Published on: November 30, 2018

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Last Updated: May 24, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Published on: March 21, 2025

Analysis of β-Amyloid-induced Abnormalities on Fibrin Clot Structure by Spectroscopy and Scanning Electron Microscopy

Analysis of β-Amyloid-induced Abnormalities on Fibrin Clot Structure by Spectroscopy and Scanning Electron Microscopy

Published on: November 30, 2018

Area of Science:

Biochemistry
Structural Biology
Biophysics

Background:

Amyloid fibrils and oligomers are linked to neurodegenerative diseases like Alzheimer's and Parkinson's.
Fibril assembly pathways influence oligomer/fibril distribution and toxicity.
Human apolipoprotein C-II (apoC-II) forms amyloid fibrils via a reversible process involving closed-loop formation and fibril dynamics.

Purpose of the Study:

To investigate the reversible self-assembly mechanism of human apoC-II amyloid fibrils.
To develop a thermodynamic model explaining fibril size distribution and closed-loop formation.
To elucidate the role of monomer isomerization and fibril dynamics in apoC-II fibrillogenesis.

Main Methods:

Fluorescence quenching and sedimentation velocity experiments with Alexa488-labeled apoC-II.
Dilution experiments with mature apoC-II fibrils.
Development and application of an equilibrium self-association model incorporating isomerization, self-assembly, and fibril dynamics.

Main Results:

Demonstrated time-dependent subunit interchange in both linear and closed-loop apoC-II fibrils.
Dilution experiments confirmed a reversible assembly pathway with shifts to smaller size distributions.
The developed model accurately described apoC-II fibril size distributions and closed-loop formation across varying concentrations (0.1-0.5 mg/ml).
Kinetic data on fibril formation and size changes were well-explained by the extended model.

Conclusions:

ApoC-II fibril formation is governed by a reversible self-assembly pathway involving monomer isomerization and isodesmic self-association.
Fibril length-dependent closed-loop formation is a key feature of apoC-II fibrillogenesis.
The model provides a thermodynamic framework for understanding apoC-II fibril equilibrium and the formation of oligomeric intermediates, relevant to age-related diseases.