Researchers at Osaka University, Japan, have found a new way to speed up the accumulation of amyloid-beta protien in a laboratory setting to better study the aggregation mechanisms in Alzheimer’s disease. Because amyloid-beta aggregation characteristics are thought to be a marker of disease, researchers suggest the new method might be applied to future diagnostic tests.
The study of aggregation mechanics of amyloid-beta is crucial to developing drugs intended to target the aggregates. But observing the build-up of protein aggregates in the lab is a slow process. Researchers have long been on the lookout for methods that might accelerate the process.
Earlier studies have shown that ultrasonic irradiation increases the aggregation rate of various proteins in solution, but it has not been clear how that happens.
The study “Nucleus factory on cavitation bubble for amyloid β fibril,” explored this method on solutions of amyloid-beta monomers and found that the increased aggregation is brought on by cavitation bubbles — formations of gas bubbles inside a liquid, repeatedly forming and collapsing when a protein solution is irradiated with an ultrasonic wave.
The complex science behind the discovery, published in the journal Scientific Reports, can be explained in simple terms. Scientists force the formation of such bubbles in a liquid holding amyloid-beta monomers, which stick to the surface of the growing bubbles, linked by surface factors attracting parts of the amyloid molecule that do not mix well with water. When a bubble collapses, protein monomers are concentrated and exposed to high temperatures, triggering the aggregation.
When the research team used acoustic pressure at a frequency of 30 kHz, the rate of aggregate formation using the new method was found to be 1,000 times greater than the natural processes.
According to a press release, the findings may impact the way Alzheimer’s diagnoses are made. Because patients who later develop Alzheimer’s, amyloid-beta has a greater capacity for aggregation. Again, the clinical applications of such studies are prevented by the slow process, so a technology speeding the process up might give rise to tests for Alzheimer’s risk.