One of the mysteries of amyloid plaque formation is how, after their long, slow formation, the speed of their progression becomes much faster.
- Andela Saric
The ability of biological molecules, such as our DNA, to replicate themselves is the foundation of life. It is a process that usually involves complex cellular machinery. However, certain protein structures manage to replicate without any additional assistance, such as the small, disease-causing protein fibres – fibrils – that are involved in neurodegenerative disorders, including Alzheimer’s and Parkinson’s.
These fibrils, known as amyloids, become intertwined and entangled with each other, causing the so-called ‘plaques’ that are found in the brains of Alzheimer’s patients. Spontaneous formation of the first amyloid fibrils is very slow, and typically takes several decades, which could explain why Alzheimer’s is usually a disease that affects people in their old age. However, once the first fibrils are formed, they begin to replicate and spread much more rapidly by themselves, making the disease extremely challenging to control.
Despite its importance, the fundamental mechanism of how protein fibrils can self-replicate without any additional machinery is not well understood. In a study published today in the journal Nature Physics, a team led by researchers from the Department of Chemistry at the University of Cambridge used a powerful combination of computer simulations and laboratory experiments to identify the necessary requirements for the self-replication of protein fibrils.
The researchers found that the seemingly complicated process of fibril self-replication is actually governed by a simple physical mechanism: the build-up of healthy proteins on the surface of existing fibrils.
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Image: Artist’s rendering of protein fibrils (in blue) and healthy proteins from computer simulations
Credit: Ivan Barun
Reproduced courtesy of the University of Cambridge
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