A boundary dance of amyloid-β stepping into dementia

December 27, 2018

Many proteins aggregate at higher concentrations and form spherical substances called oligomers and acicular substances called amyloid fibrils. These protein aggregates cause more than 30 kinds of diseases, for example, Alzheimer's disease is thought to be caused by the oligomers and amyloid fibrils formed by aggregation of amyloid-β (Aβ) peptides. It is known that aggregation of Aβ peptide is accelerated at a hydrophilic/hydrophobic interface such as a cell membrane surface. However, why the Aβ peptides tend to aggregate on the surface has not yet been well understood.

The research group at Exploratory Research Center on Life and Living Systems and Institute for Molecular Science, Japan worked on this problem using molecular dynamics simulations and nuclear magnetic resonance spectroscopy experiments. They found that the Aβ peptides tend to gather at the hydrophilic/hydrophobic interface. That is, the local concentration of Aβ at the interface is higher than that in bulk water solution. In addition, β-hairpin structures are formed more at the interface than in the bulk water solution. In the β-hairpin structure, as shown in the figure, a part of the Aβ peptide extends straight and forms intramolecular hydrogen bonds. Therefore, another Aβ peptide that comes close to this peptide is easy to make intermolecular hydrogen bonds and tends to aggregate. In this way, the research group clarified that the reason for accelerating the aggregation of the Aβ peptides on the cell membrane surface is that not only the Aβ peptide tends to have high concentration on the cell membrane surface but also it takes a structure that tends to bind to each other.

This discovery enables us to elucidate the mechanism by which the Aβ peptide aggregates on the membrane surface of nerve cells. Elucidating this mechanism will be applied to developing inhibitors against the causative substances of Alzheimer's disease in the future.
-end-


National Institutes of Natural Sciences

Related Peptides Articles from Brightsurf:

Peptides+antibiotic combination may result in a more effective treatment for leishmaniasis
A combination of peptides and antibiotics could be key to eliminating the parasite causing leishmaniasis and avoiding the toxicity to people and animals caused by current drugs.

Designer peptides show potential for blocking viruses, encourage future study
Chemically engineered peptides, designed and developed by a team of researchers at Rensselaer Polytechnic Institute, could prove valuable in the battle against some of the most persistent human health challenges.

Tracking down cryptic peptides
Using a newly developed method, researchers from the University of Würzburg, in cooperation with the University Hospital of Würzburg, were able to identify thousands of special peptides on the surface of cells for the first time.

Synthesis of prebiotic peptides gives clues to the origin of life on Earth
Coordination Compounds Lab of Kazan Federal University started researching prebiotic peptide synthesis in 2013 with the use of the ASIA-330 flow chemistry system.

Peptides that can be taken as a pill
Peptides represent a billion-dollar market in the pharmaceutical industry, but they can generally only be taken as injections to avoid degradation by stomach enzymes.

Harnessing psyllid peptides to fight citrus greening disease
BTI, USDA and UW scientists have identified peptides in the Asian citrus psyllid, an insect that spreads the bacterium that causes citrus greening disease (huanglongbing, HLB).

New technique has potential to protect oranges from citrus greening
Citrus greening, also called Huanglongbing (HLB), is devastating the citrus industry.

Researchers show what drives a novel, ordered assembly of alternating peptides
A team of researchers has verified that it is possible to engineer two-layered nanofibers consisting of an ordered row of alternating peptides, and has also determined what makes these peptides automatically assemble into this pattern.

Origin of life insight: peptides can form without amino acids
Peptides, one of the fundamental building blocks of life, can be formed from the primitive precursors of amino acids under conditions similar to those expected on the primordial Earth, finds a new UCL study published in Nature.

Ragon Institute study identifies viral peptides critical to natural HIV control
Investigators at the Ragon Institute of MGH, MIT and Harvard have used a novel approach to identify specific amino acids in the protein structure of HIV that appear critical to the ability of the virus to function and replicate.

Read More: Peptides News and Peptides Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.