Nav: Home

From champagne bubbles, dance parties and disease to new nanomaterials

November 22, 2016

WASHINGTON, D.C., Nov. 22, 2016 -- Whether it is clouds or champagne bubbles forming, or the early onset of Alzheimer's disease or Type 2 diabetes, a common mechanism is at work: nucleation processes.

Nucleation processes are a first step in the structural rearrangement involved in the phase transition of matter: a liquid morphing into a gas, a gas becoming a liquid and so on. Clouds, boiling water, bubbles, and some disease stages are all characterized by the formation of a new thermodynamic phase which requires some of the smallest units of the new structure to form before this new phase can grow. Understanding this process is critical for preventing, halting or treating cases of nucleation processes gone wrong -- such as in human disease. Now, a team of researchers from University College London and the University of Cambridge in Great Britain in collaboration with Harvard University have made headway toward understanding this problem from a molecular point of view in a new study. Their finding is significant across an array of phenomena, from human disease to nanotechnology.

"Perhaps an intuitive example of nucleation would be the way in which a quiet dinner party suddenly transforms into a dancing one; such a transition usually requires several people to start dancing at once, acting as a 'nucleus' around which the dancing party assembles," explained An?ela Šari?, lead coauthor at the University College London and the University of Cambridge. The results of this study will appear this week in The Journal of Chemical Physics, from AIP Publishing.

"As commonly observed, if this group of dancers is too small, it tends to be ignored; however, above a certain size, this dancing nucleus attracts more and more people, eventually dominating the room," adds Thomas Michaels, the other lead coauthor. This minimum number of dancing people required to transform the party is what in thermodynamic terms is commonly known as the "critical nucleus."

In their research, the team considers a particularly intriguing example of a nucleated process: the formation of protein filaments. Many filamentous structures of proteins such as actin and tubulin are key for the growth, structural formation, movement and division of cells. They are an essential characteristic of living systems. However, protein filaments can also be disease-causing: Over 50 common disorders, including Alzheimer's disease, Parkinson's disease, and Type 2 diabetes, are associated with the formation and deposition in the brain or other organs of protein filaments commonly known as amyloids.

Using a combination of theory and computer simulations the authors explored the nucleation of protein filaments. Their goal was to establish the fundamental physical principles behind it. Their results showed that a seemingly complicated process of fibril nucleation is actually governed by a relatively simple physical mechanism: Unorganized clusters of proteins -- so-called oligomers -- are formed initially.

These structures do not resemble protein filaments yet, but have to undergo a structural conversion before they can grow into mature filaments, Šari? explained. They found that among many different steps in fibril nucleation, the shape change inside oligomers is the rate-determining step. Therefore, conformational changes in the protein inside oligomers (leading to the formation of β-sheet configurations) are crucial to understand fibril nucleation. Previously, the size of critical nucleus was considered the rate-determining factor.

The study represents an important step forward in the mechanistic understanding of the way in which protein filaments form. Such an understanding is key for studying the early stages in the onset of diseases associated with protein aggregation, as oligomers are increasingly believed to be the prime cause for cellular toxicity.

"Understanding which microscopic-level steps are determining for the formation of protein fibrils can provide invaluable information for designing rational therapies aimed at suppressing pathogenic oligomer generation," Šari? explained

Moreover, due to their unique physicochemical properties, protein filaments are finding extensive applications in materials science as biomaterials for nanotechnology," Michaels said. "Better control of filamentous growth would benefit the production of novel functional materials that have extensive applications in materials science as biomaterials for nanotechnology."
The article, "Kinetics of spontaneous filament nucleation via oligomers: Insights from theory and simulation," is authored by An?ela Šari?, Thomas C. T. Michaels, Alessio Zaccone, Tuomas P.J. Knowles and Daan Frenkel. The article will appear in the journal The Journal of Chemical Physics on Nov. 22, 2016 (DOI: 10.1063/1.4965040). After that date, it can be accessed at


The Journal of Chemical Physics publishes concise and definitive reports of significant research in the methods and applications of chemical physics. See

American Institute of Physics

Related Diabetes Articles:

The role of vitamin A in diabetes
There has been no known link between diabetes and vitamin A -- until now.
Can continuous glucose monitoring improve diabetes control in patients with type 1 diabetes who inject insulin
Two studies in the Jan. 24/31 issue of JAMA find that use of a sensor implanted under the skin that continuously monitors glucose levels resulted in improved levels in patients with type 1 diabetes who inject insulin multiple times a day, compared to conventional treatment.
Complications of type 2 diabetes affect quality of life, care can lead to diabetes burnout
T2D Lifestyle, a national survey by Health Union of more than 400 individuals experiencing type 2 diabetes (T2D), reveals that patients not only struggle with commonly understood complications, but also numerous lesser known ones that people do not associate with diabetes.
Type 2 diabetes and obesity -- what do we really know?
Social and economic factors have led to a dramatic rise in type 2 diabetes and obesity around the world.
A better way to predict diabetes
An international team of researchers has discovered a simple, accurate new way to predict which women with gestational diabetes will develop type 2 diabetes after delivery.
The Lancet Diabetes & Endocrinology: Older Americans with diabetes living longer without disability, US study shows
Older Americans with diabetes born in the 1940s are living longer and with less disability performing day to day tasks than those born 10 years earlier, according to new research published in The Lancet Diabetes & Endocrinology journal.
Reverse your diabetes -- and you can stay diabetes-free long-term
A new study from Newcastle University, UK, has shown that people who reverse their diabetes and then keep their weight down remain free of diabetes.
New cause of diabetes
Although insulin-producing cells are found in the endocrine tissue of the pancreas, a new mouse study suggests that abnormalities in the exocrine tissue could cause cell non-autonomous effects that promotes diabetes-like symptoms.
The Lancet Diabetes & Endocrinology: Reducing sugar content in sugar-sweetened drinks by 40 percent over 5 years could prevent 1.5 million cases of overweight and obesity in the UK and 300,000 cases of diabetes
A new study published in The Lancet Diabetes & Endocrinology journal suggests that reducing sugar content in sugar sweetened drinks (including fruit juices) in the UK by 40 percent over five years, without replacing them with any artificial sweeteners, could prevent 500,000 cases of overweight and 1 million cases of obesity, in turn preventing around 300,000 cases of type 2 diabetes, over two decades.
Breastfeeding lowers risk of type 2 diabetes following gestational diabetes
Women with gestational diabetes who consistently and continuously breastfeed from the time of giving birth are half as likely to develop type 2 diabetes within two years after delivery, according to a study from Kaiser Permanente published today in Annals of Internal Medicine.

Related Diabetes Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...